HELP ME PLS I DONT UNDERSTAND :(((( WILL MARK BRAINLIEST AND ROBUX

HELP ME PLS I DONT UNDERSTAND :(((( WILL MARK BRAINLIEST AND ROBUX

Answers

Answer 1

Answer:

H  -2 ≤x≤4

Step-by-step explanation:

The domain is the input values or the x values

-2 ≤x≤4

Answer 2

Answer:

H

Step-by-step explanation:

You can see because the answer starts with -2.


Related Questions

Find out the coordinates

Answers

answer:

c) (0,-8)

reason:

it may be easiest to visualize by putting (-3,-5) and (-6,-2) on a graph
you can see that to get from C to B you have to add 3 to the x value and subtract 3 from the y value
do the same to point B, which will give you (0,-8)

Jack is packing snacks for him and his three brothers. He bought 10 1/2 ounces of pretzels. He wants to put the pretzels into bags so that he and his three brothers have the same of pretzels in their bags. How many ounces of pretzels should he put into each bag?

Answers

Answer:

3.5

Step-by-step explanation:

total pretzel=10 1/2 or10.5

no. of brother = 3

now,

10.5 pretzel for each borther= 10.5/3

=3.5 ans

what is the domain and range of f(x)=2x+3

Answers

Answer:

D:{x∈R}

R:{y∈R}

Step-by-step explanation:

This is just a linear function. I know this because the degree of the x-variable is 1.

Domain and range are sets of possible values the function can have - though not necessarily at the same time.

Thus, there are no restrictions to the domain and range unless context is given.

Therefore, the domain and range is:

D:{x∈R}

R:{y∈R}

Evaluate (5-3)^3+ -3^2(6-3)

Answers

Steps to solve:

(5 - 3)^3 + (-3)^2(6 - 3)

~Simplify

2^3 + (-3)^2(3)

2^3 + (-3)^6

~Solve exponents

8 + (-729)

~Subtract

-721

Best of Luck!

Solve the equation -4 = 5 -x.

Answers

X=5+4
X=9




So the answer is, x=9

Answer:

when x goes opposite side of equals to sign of x changes and same goes with 4 then x=5+4 then the answer will be 9

please help :)) ❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

Answers

34 is a rational number hole this helped :))

What is the fractional equivalent of the repeating decimal 0.2 ?​

Answers

Answer:

1/5

Step-by-step explanation:

I put it in a graphing calculator and converted it into a fraction

Perform the following operations and write the answers in radical form. Part A:√7+√3+√98−√18 Part B:3√5−3√11+2√121−3√90

Answers

Answer:

[tex]\sqrt{7}+\sqrt{3}+4\sqrt{2}[/tex] [tex]3\sqrt{5}-3\sqrt{11}+22-9\sqrt{10}[/tex]

Step-by-step explanation:

Part A ;

[tex]\sqrt{7} +\sqrt{3} +\sqrt{98} -\sqrt{18} \\\\\sqrt{98}=7\sqrt{2}\\\sqrt{18}=3\sqrt{2}\\\\=\sqrt{7}+\sqrt{3}+7\sqrt{2}-3\sqrt{2}\\\\\mathrm{Add\:similar\:elements:}\:7\sqrt{2}-3\sqrt{2}=4\sqrt{2}\\\\=\sqrt{7}+\sqrt{3}+4\sqrt{2}[/tex]

Part B ;

[tex]3\sqrt{5} - 3\sqrt{11} + 2\sqrt{121} -3\sqrt{90} \\\\2\sqrt{121}=22\\3\sqrt{90}=9\sqrt{10}\\\\=3\sqrt{5}-3\sqrt{11}+22-9\sqrt{10}[/tex]

help me asap i don't know this

Answers

Answer:

y = 3

Step-by-step explanation:

Step 1: Write equation

-2(7 - y) + 4 = -4

Step 2: Subtract 4 on both sides

-2(7 - y) = -8

Step 3: Distribute

-14 + 2y = -8

Step 4: Add 14 to both sides

2y = 6

Step 5: Divide both sides by 2

y = 3

The velocity of an object is given by the following function defined on a specified interval. Approximate the displacement of the object on this interval by subdividing the interval into the indicated number of subintervals. Use the left endpoint of each subinterval to compute the height of the rectangles. v = 1/(2t + 4) (m/s) for for 0 ≤ t ≤ 88; n = 22

Answers

Answer:

The displacement of the object on this intervals is 1.33 m.

Step-by-step explanation:

Given that,

The function of velocity is

[tex]v=\dfrac{1}{2t+4}\ m/s[/tex]

For 0 ≤ t ≤8 , n = 2

We need to calculate the intervals

Using formula for intervals

For, n = 1

[tex]\Delta x=\dfrac{t_{f}-t_{i}}{n}[/tex]

[tex]\Delta x=\dfrac{8-0}{2}[/tex]

[tex]\Delta x=4[/tex]

So, The intervals are (0,4), (4,8)

We need to calculate the velocity

Using given function

[tex]v=\dfrac{1}{2t+4}[/tex]

For first interval (0,4),

Put the value into the formula

[tex]v_{0}=\dfrac{1}{2\times0+4}[/tex]

[tex]v_{0}=\dfrac{1}{4}[/tex]

For first interval (4,8),

Put the value into the formula

[tex]v_{4}=\dfrac{1}{2\times4+4}[/tex]

[tex]v_{4}=\dfrac{1}{12}[/tex]

We need to calculate the total displacement

Using formula of displacement

[tex]D=(v_{0}+v_{4})\times(\Delta x)[/tex]

Put the value into the formula

[tex]D=(\dfrac{1}{4}+\dfrac{1}{12})\times4[/tex]

[tex]D=1.33\ m[/tex]

Hence, The displacement of the object on this intervals is 1.33 m.

The displacement of the object whose velocity function is given is 1.33 m

The given parameters are:

[tex]\mathbf{v = \frac{1}{2t + 4},\ 0 \le t \le 8; n =2}[/tex]

The end point of intervals is calculated as:

[tex]\mathbf{\triangle t = \frac{b - a}{n}}[/tex]

So, we have:

[tex]\mathbf{\triangle t= \frac{8 - 0}{2}}[/tex]

[tex]\mathbf{\triangle t = \frac{8}{2}}[/tex]

[tex]\mathbf{\triangle t= 4}[/tex]

So, the intervals are (0,4) and (4,8)

Calculate the velocity at the beginning of each interval

[tex]\mathbf{v_0 = \frac{1}{2(0) + 4} = \frac 14}[/tex]

[tex]\mathbf{v_4 = \frac{1}{2(4) + 4} = \frac 1{12}}[/tex]

Calculate the displacement (S) using:

[tex]\mathbf{S = (v_0 + v_4) \times \triangle t}[/tex]

So, we have:

[tex]\mathbf{S = (1/4 + 1/12) \times 4}[/tex]

Expand

[tex]\mathbf{S = 1 + 1/3}[/tex]

Add

[tex]\mathbf{S = 1 \frac 13}[/tex]

Express as decimals to 2 decimal places

[tex]\mathbf{S = 1.33}[/tex]

Hence, the displacement is 1.33 m

Read more about displacement at:

https://brainly.com/question/17131235

Evaluate x^2 + 2x + 3
for x = 4

Answers

Steps to solve:

x^2 + 2x + 3 when x = 4

~Substitute

4^2 + 2(4) + 3

~Simplify

16 + 8 + 3

~Add

24 + 3

~Add

27

Best of Luck!

.At a certain animal shelter, the ratio of puppies to adult dogs is 7 to 4. This week there are a total of55 dogs in the shelter. How many puppies are in the shelter this week? How many adult dogs are in the shelter this week

Answers

Answer:

There are 35 adult dogs and 20 puppies

Step-by-step explanation:

Represent the puppies with P and the Adult dogs with A

Given

[tex]A : P = 7 : 4[/tex]

Dogs = 55

Required

Determine A and P

First, we need to sum the ratios;

[tex]Total = A + P[/tex]

[tex]Total = 7 + 4[/tex]

[tex]Total = 11[/tex]

Adult Dogs is then calculated as follows;

[tex]A = \frac{A\ Ratio}{Total} * Dogs[/tex]

[tex]A = \frac{7}{11} * 55[/tex]

[tex]A = \frac{385}{11}[/tex]

[tex]A = 35[/tex]

Puppies is calculated by subtracting the number of adult dogs from the total

[tex]P = Dogs - Adult\ Dogs[/tex]

[tex]P = 55 - 35[/tex]

[tex]P = 20[/tex]

Hence;

There are 35 adult dogs and 20 puppies

I have 4 questions

1. Suppose point T is between points R and V on a line. If RT = 63 units and RV = 131 units,
then what is TV?

131

194

68

80

2.Given point P is between M and N. If MN = 26, MP = x + 4, and PN = 2x + 1, what is the value of x?

x = 3

x = 7

x = 12.5

x = 22

3.Given M is the midpoint of HJ, HM = 4x - 12, and MJ = 3x + 9. What is the value of x?

4.If D is the midpoint of CE, DE = 2x + 4, and CE = 6x + 2, then what is CD?

Answers

The first one is C. 68. The second one is B. 7. The third one is x = 21. The fourth one is CD = 10

Help me please this is math

Answers

Answer:

c) none of the above

Step-by-step explanation:

this is because we should put the equation like:

1/3 - (-4/3) because the distance is 5 units and

1/3 + 4/3 = 5/3

this is because (-) × (-) = (+)

an airplane is traveling at 400 miles per hour. which equation can be used to find the total distance the plane will travel in h hours.

Answers

Answer:

y=400h

Where y is distance and h is time.

The average spending at Neco's salad bar is $8.73 with a standard deviation of $3.41. The distribution follows t-distribution. The management is interested in the middle 90% of the customers (spending wise) as it believes that they represent their true customer base. What will be the difference between the upper and lower spending cut-offs which define the middle 90% of the customers if the sample contains 41 customers

Answers

Answer:

Difference between upper and lower limits is : 1,816

Step-by-step explanation:

A CI (confidence interval ) for  t student distribution is:

( μ₀  - t(α/2)* s/√n  ;    μ₀  + t(α/2)* s/√n )

Where:

μ₀  is the mean and s the standard deviation of the dstribution

n size of the sample

CI = 90 %     means   α = 10 %    α = 0,1      α/2  = 0,05

and degree of freedom   df = n - 1   df = 40

From t student table we get:

tα/2  =  1,6839

Then:

t(α/2)* s/√n  =  1,6839* 3,41/√40

t(α/2)* s/√n  =  0,908

8,73 - 0,908   =  7,822

8,73 + 0,908  = 9,638

CI (90%)  =  ( 7,822  ;  9,638 )

Difference between upper and lower cut-offs points is:

Δ = 1,816

What number line correctly shows one way to find 2-6 ?

Answers

0? Because it separates the negative and positives??

Which of the following are dimensionally consistent? (Choose all that apply.)(a) a=v / t+xv2 / 2(b) x=3vt(c) xa2=x2v / t4(d) x=vt+vt2 / 2(e) v=x2 / at3(f) a3=x2v / t5(g) x=t(h) v=5at

Answers

Complete Question

The  complete question is shown on the first uploaded image

Answer:

A

is dimensionally consistent

B

is not dimensionally consistent

C

is dimensionally consistent

D

is not dimensionally consistent

E

is not dimensionally consistent

F

is dimensionally consistent

G

is dimensionally consistent

H

is not dimensionally consistent

Step-by-step explanation:

From the question we are told that

   The equation are

                        [tex]A) \   \  a^3  =  \frac{x^2 v}{t^5}[/tex]

                       

                       [tex]B) \   \  x  =  t [/tex]

 

                       [tex]C \ \ \ v  =  \frac{x^2}{at^3}[/tex]

 

                      [tex]D \ \ \ xa^2 = \frac{x^2v}{t^4}[/tex]

                      [tex]E \ \ \ x  = vt+ \frac{vt^2}{2}[/tex]

                     [tex]F \ \ \  x = 3vt[/tex]

 

                    [tex]G \ \ \  v =  5at[/tex]

 

                    [tex]H \ \ \  a  =  \frac{v}{t} + \frac{xv^2}{2}[/tex]

Generally in dimension

     x - length is represented as  L

     t -  time is represented as T

     m = mass is represented as M

Considering A

           [tex]a^3  =  (\frac{L}{T^2} )^3 =  L^3\cdot T^{-6}[/tex]

and    [tex]\frac{x^2v}{t^5 } =  \frac{L^2 L T^{-1}}{T^5}  =  L^3 \cdot T^{-6}[/tex]

Hence

           [tex]a^3  =  \frac{x^2 v}{t^5}[/tex] is dimensionally consistent

Considering B

            [tex]x =  L[/tex]

and      

            [tex]t = T[/tex]

Hence

      [tex]x  =  t[/tex]  is not dimensionally consistent

Considering C

     [tex]v  =  LT^{-1}[/tex]

and  

    [tex]\frac{x^2 }{at^3} =  \frac{L^2}{LT^{-2} T^{3}}  =  LT^{-1}[/tex]

Hence

   [tex]v  =  \frac{x^2}{at^3}[/tex]  is dimensionally consistent

Considering D

    [tex]xa^2  = L(LT^{-2})^2 =  L^3T^{-4}[/tex]

and

     [tex]\frac{x^2v}{t^4}  = \frac{L^2(LT^{-1})}{ T^5} =  L^3 T^{-5}[/tex]

Hence

    [tex] xa^2 = \frac{x^2v}{t^4}[/tex]  is not dimensionally consistent

Considering E

   [tex]x =  L[/tex]

;

   [tex]vt  =  LT^{-1} T =  L[/tex]

and  

    [tex]\frac{vt^2}{2}  =  LT^{-1}T^{2} =  LT[/tex]

Hence

   [tex]E \ \ \ x  = vt+ \frac{vt^2}{2}[/tex]   is not dimensionally consistent

Considering F

     [tex]x =  L[/tex]

and

    [tex]3vt = LT^{-1}T =  L[/tex]      Note in dimensional analysis numbers are

                                                       not considered

  Hence

       [tex]F \ \ \  x = 3vt[/tex]  is dimensionally consistent

Considering G

    [tex]v  =  LT^{-1}[/tex]

and

    [tex]at =  LT^{-2}T =  LT^{-1}[/tex]

Hence

      [tex]G \ \ \  v =  5at[/tex]   is dimensionally consistent

Considering H

     [tex]a =  LT^{-2}[/tex]

,

       [tex]\frac{v}{t}  =  \frac{LT^{-1}}{T}  =  LT^{-2}[/tex]

and

    [tex]\frac{xv^2}{2} =  L(LT^{-1})^2 =  L^3T^{-2}[/tex]

Hence

    [tex]H \ \ \  a  =  \frac{v}{t} + \frac{xv^2}{2}[/tex]  is not dimensionally consistent

We want to see which ones of the given expressions are dimensionally consistent. We will see that the correct options are:

a) x = 3*v*th) v = 5*a*t

What means to be dimensionally consistent?

This means that we have the same units in the left and in the right side of the equation.

The units are:

a = [m/s^2]x = [m]v = [m/s]t = [s]

Now we can analyze the expressions to see the units in each one, I will show you how to do it:

a) a = v/t + x*v^2

Replacing the units we have:

[m/s^2] = [m/s]/[s] + [m]*[m^2/s^2]

[m/s^2] = [m/s^2] + [m^3/s^2]

You can see that we have an m^3 in the right side, so these are not equivalent.

b) x = 3*v*t

Replacing the units we have:

[m] = 3*[m/s]*[s] = 3*[m]

So yes, the units are the same in both sides, so this is dimensionally consistent.

With the same procedure we can see that:

c) [m^3/s^2] = [m^3/s]                not consistentd) [m] = [m] + [m*s]                     not consistente) [m/s] = [m^2]                           not consistentf) [m^3/s^6] = [m^3/s]                 not consistentg) [m] = [s]                                   not consistenth) [m/s] = 5*[m/s]                        consistent

So the correct options are b and h.

If you want to learn more about dimensions, you can read:

https://brainly.com/question/20384972

Question 1 (1 point)
When simplified [9(7 – 3) + 13] - [11 - (6 + 9)] equals:
53
39
43
None of these

Answers

Answer:45

Step-by-step explanation:

[9(7-3)+13]-[11-(6+9)]

[9(4)+13]-[11-(15)]

[36+13]-[4]

49-4

45

Answer: The answer is 53

Angles 1 and 2 form a right angle. 2 lines form a right angle. Another line extends between the 2 lines to form 2 angles. The top angle is labeled 1, and the bottom angle is labeled 2. Which word describes their measures? linear congruent complementary supplementary

Answers

Answer:

complementary

Step-by-step explanation:

yes

The word that describes their measures of ∠1 and ∠2 is: complementary.

Recall:

Angles that are complementary are angles whose sum equals 90 degrees.A right angle equals 90 degrees.

From the information given, we know that:

m∠1 and m∠2 forms a right angle.

Since a right angle = 90 degrees, therefore:

m∠1 + m∠2 = 90° (complementary)

Therefore, the word that describes their measures of ∠1 and ∠2 is: complementary.

Learn more about complementary angles on:

https://brainly.com/question/11242655

Write an equation in slope-intercept form (y = mx + b).

A vertical line passing through (1, -4).

Answers

Answer:

x=1

Step-by-step explanation:

Anytime there is a vertical line, the y value becomes infinite as the line goes on forever. The only restriction on the line is on the x value of your coordinate. The same goes for a horizontal line, only the x value would become infinite and the y value would be constant.

Vertical Line: (x,∞)

Horizontal Line: (∞,y)

-1/2(-6x -5/2) +1= 9x

Answers

X = 7/12 or another way x= 0.583

Answer:

x=3/8

Step-by-step explanation:

Multiplique dentro del paréntesis por -1/2.Después de haber multiplicado le ecuación le quedará así 3x + 5/4 +1 = 9x.Ahora vamos a calcular la suma de la ecuación y quedará a 3x + 9/4 =9x.Después vamos a multiplicar ambos lados de la ecuación por 4 y quedará a 12x + 9= 36x.Luego vamos a mover la constante ( que es 9) al lado derecho y cambié su signo y quedará a 12x = 36x - 9.Después vamos agrupar los términos semejantes ( en este caso x) y quedará a -24x = -9.Finalmente vamos a dividir ambos lados de la ecuación entre -24 y la respuesta nos quedará a x = 3/8.

You have a bin full of the letters HGUSTWQ. If four letters are drawn at random, what is the probabilty the letters drawn will spell the word GUST ( in the order they are drawn )?

Answers

Answer:

see I need help for chemistry pls anyone here helps me I must submit before 10:30

What is the sum of Negative 1 + (negative 3)?

Answers

Answer:

[tex]\huge\boxed{-4}[/tex]

Step-by-step explanation:

=> [tex]\sf -1 + (-3)[/tex]

According to the rule [tex]\sf + * - = -[/tex]

=> [tex]\sf -1-3[/tex]

=> -4

Answer:

-4

Step-by-step explanation:

-1 + (-3)

To add two negative numbers, add their absolute values, and make the answer negative.

The absolute values of -1 and -3 are 1 and 3. We add 1 + 3 and get 4.

Then we make the answer negative.

-1 + (-3) = -4

I
rep
What is the solution of 4(2y + 1) = 2(y - 13)
What is the answer

Answers

Answer:

- 5

Step-by-step explanation:

Step 1:

4 ( 2y + 1 ) = 2 ( y - 13 )

Step 2:

8y + 4 = 2y - 26

Step 3:

6y + 4 = - 26

Step 4:

6y = - 30

Answer:

y = - 5

Hope This Helps :)

y=1/4x + 6
that passes through the point (-4, 3) in slope-intercept form.

Answers

Answer:

The answer is

[tex]y = \frac{1}{4} x + 4[/tex]

Step-by-step explanation:

Equation of a line is y = mx + c

where

m is the slope

c is the y intercept

To find the equation of the parallel line we must first find the slope of the original line.

The equation is

y = 1/4x + 6

Comparing with the general equation above

Slope = 1/4

Since the lines are parallel their slope are also the same

That's

Slope of parallel line = 1/4

So the equation of the parallel line using point (-4 , 3) and slope 1/4 is

[tex]y - 3 = \frac{1}{4} (x + 4) \\ y - 3 = \frac{1}{4} x + 1 \\ y = \frac{1}{4} x + 1 + 3[/tex]

We have the final answer as

[tex]y = \frac{1}{4} x + 4[/tex]

Hope this helps you

G(x) = 2x^2 and h(x) = √x^2+1 .What is (goh)^-1 and is it a function?

Answers

Answer:

Step-by-step explanation:

Hello,

[tex](goh)(x)=g(h(x))=2\left( \sqrt{x^2+1}\right)^2=2(x^2+1)\\\\x=(goh)((goh)^{-1}(x))=2((goh)^{-1}(x)^2+1)\\ \\\left((goh)^{-1}(x)\right)^2=\dfrac{x}{2}-1=\dfrac{x-2}{2}\\ \\(goh)^{-1}(x)=\sqrt{\dfrac{x-2}{2}}[/tex]

And this is a function defined for x-2 [tex]\geq[/tex] 0, meaning x [tex]\geq[/tex] 2

Thanks

Which of the following is an example of a translation?
a) The preimage is twice the size as the image.
b) The preimage is moved 5 spaces up.
c) The preimage is rotated 90 degrees about the origin.
d) The image is a mirror reflection of the preimage.



Answers

Answer:

Step-by-step explanation:

a)the pre image us twice the same size as the image

If KL = x + 4, LM = 2, and KM = 5x − 3, what is KL?

Answers

Step-by-step explanation:

then put x valule into KL equation

Martin's average score after 4 tests is 89. What score on the 5th test would bring Martin's average up to exactly 90?

Answers

Answer:

104

Step-by-step explanation:

89x4=356 90x5=450

450=356=104

Answer:

94

Step-by-step explanation:

((89x4)+94) divided by 5 = 90

Other Questions
what should we do to Maintain sympathy and cooperation The 13 original colonies were primarily located along the A Atlantic Ocean B Gulf of Mexico C Mississippi RiverD Great Lakes Ap chem, please help with number 31!! One liter of a 0.1M Tris buffer (pKa=8.3) is adjusted to a pH of 2.0. a. What are the concentrations of the conjugate base and weak acid at this pH? b. What is the pH when 1.5mL of 3.0M HCl is added to this buffer? Is Tris a good buffer at this pH? Why? c. What is the pH when 1.5mL of 3.0M NaOH is added to this buffer? Are the bonds that chlorine forms with sodium (to form NaCl) and with carbon (to form CCl4) the same in both compounds? WILL GIVE BRAINLIEST! Make a sentence using these words parque / Pablo / y / correr / perro / su / por / el True or false? (-x)^4 = -x^4 Explain your answer. Which of the following best describes the circled part of thestatement?7x + 9= 40 Technician A says independent shops are not affiliated with vehicle manufacturers, but it is easy for technicians who work in these shops to get manufacturer training on new technologies. Technician B says independent shops are not affiliated with vehicle manufacturers, making it harder for independent technicians to access training on new vehicle technology. Who is correct? Technician A Technician A Both A and B Both A and B Neither A nor B Neither A nor B Technician B Technician B What is the mass, in grams, of a cube of copper that has a volume of 62.2 cm3? In what ways are driverless cars safer than human drivers? Items 2-4. Points P, Q, and Sarecollinear.(3x - 5)0(x + 1)s2. What is the value of x?3. What is m ZPQR?will11. M4. If a ray QT bisects ZRQS, whatwill be the measure of one of theresulting angles?mof5. Points L, M, and N are collinear.You are given LM = 5 and LN = 17.What is a possible value of MN?Flb6. Ray BD bisects ZABC so thatmZDBC = x + 6 andmZABD = 2x - 12. What is x? Who does a second person pronoun refer to?It refers to the person spoken aboutIt refers to more than one person or thing.It refers to the person who is speaking or writing,It refers to the person spoken to, In the poem "Barbara Frietchie, what is true about each rhyming couplets? Explain the two ways a plains tribe member could gain social status Look at the map of the Empire of Charlemagne. Notice the areas he conquered before 814. How does the size of this area compare with the extent of the kingdom of the Franks in 768? What parts of present-day Italy did Charlemagne conquer? How might this affect the pope? Select the correct answer from each drop-down menu. (Brainlist) Read through the following passage about the basic beliefs of Judaism. Choose the correct word or phrase to complete each sentence. Many of the central beliefs of Judaism are listed in the _______, such as the importance of observing the Sabbath or practicing self-control instead of stealing or committing murder. One of the most important ideas in Judaism involves ones relationship with God. Jews work to ____by doing good deeds for others and praying to God every day. Some Jews also look forward to the coming of_____, who they believe will bring peace to the world and restore them to the promised land of Canaan. Plz, help :( please answer this question The temperature was -1 F, 5 F, 8 F, and 6 F. What was the average temperature? Innovations like desalination allowed people living in areas without adequate freshwater sources to adapt to there environment?