Answer:
It costs $120 to build a fence.
Step-by-step explanation:
We first need to find the length of the longer side and the shorter side of the rectangle. So, let's call x the length of the rectangle and y the width of the rectangle.
If the rectangle is 2 times as long as it is wide, we can write the following equation:
x = 2y
If the perimeter is 60 feet, we can write the equation
2x + 2y = 60
Then, replacing the first equation on the second and solving for x, we get:
2x + x = 60
3x = 60
3x/3 = 60/3
x = 20 feet
Now, we can find the value of y
x = 2y
20 = 2y
20/2 = 2y/2
10 = y
Therefore, the length of the rectangle is 20 feet and the width is 10 feet.
Now, we can calculate the cost, multiplying the longer sides by $1.75 and the shorter sides by $2.5, so
C = 20(1.75) + 20(1.75) + 10(2.5) + 10(2.5)
C = 120
So, it costs $120 to build a fence.