Final answer:
To calculate the perimeter of the given rectangle, multiply the width and length by 2 and sum them together, resulting in 25x + 3 feet.
Step-by-step explanation:
The student has a rectangle with given dimensions for the width and length in terms of x. To find the perimeter of the rectangle, we use the formula P = 2l + 2w, where l is the length and w is the width.
In this case, the width (w) is 4x - 8.5 feet and the length (l) is 8.5x + 10 feet. Therefore, the perimeter (P) can be calculated as:
P = 2(4x - 8.5) + 2(8.5x + 10)
Simplifying the expression:
P = 8x - 17 + 17x + 20
P = (8x + 17x) + (20 - 17)
P = 25x + 3
So, the perimeter of the rectangle is 25x + 3 feet.