Area of a rectangle: length * width
You are given the width, 11 km, so plug in 11 for width and 154 for area in the formula for area of a rectangle and solve for length (x).
x * 11 = 154
rewritten as: 11x = 154
Divide both sides by 11.
x = 14
Your answer is C) 14 km.
Answer:
b
Step-by-step explanation:
Ok I dont know how to do this im so sorry
If the width and the length of the rectangle are called x and y, the area is given by:
![A = xy](https://tex.z-dn.net/?f=A%20%3D%20xy)
The perimeter of the rectangle is given by:
![P = 2x + y = 20100 feet](https://tex.z-dn.net/?f=P%20%3D%202x%20%2B%20y%20%3D%2020100%20feet)
Combining both equations by eliminating the y variable:
![A = x(20100 - 2x) = 20100x - 2x^2](https://tex.z-dn.net/?f=A%20%3D%20x%2820100%20-%202x%29%20%3D%2020100x%20-%202x%5E2)
The maximum area can be found by taking the derivative with respect to x and setting it to zero.
![\frac{dA}{dx} = 20100 - 4x = 0](https://tex.z-dn.net/?f=%20%5Cfrac%7BdA%7D%7Bdx%7D%20%3D%2020100%20-%204x%20%3D%200)
Solving for x:
![4x = 20100 \\ x = 5025](https://tex.z-dn.net/?f=4x%20%3D%2020100%20%5C%5C%20x%20%3D%205025)
Solving for y:
Answer:
34
Step-by-step explanation: