your backyard is 25 feet longer than it is wide. its area is 7854 square feet. its width is feet

Question

Help me find the answer please 

Answer 1

your backyard is 25 feet longer than it is wide

l = w + 25, w = l - 25

its area is 7854 square feet. its width is feet

A = 7854 = lw = (l - 25)l

7854 = l^2 - 25l

l^2 - 25l - 7854 = 0

l = 102, l = -77

Discard l = -77 because a length can't be negative

w = 77

(I used the quadratic eq to solve this)