Answer:
see explanation
Explanation:
let the length be l then width = l + 5 ( 5 more than length )
Given area = 84, then
l(l + 5) = 84 ← distribute left side
l² + 5l = 84 ( subtract 84 from both sides )
l² + 5l - 84 = 0 ← in standard form
Consider the factors of the constant term ( - 84) which sum to give the coefficient of the l- term ( + 5)
The factors are + 12 and - 7, since
12 × - 7 = - 84 and 12 - 7 = 5, thus
(l + 12)(l - 7) = 0 ← in factored form
Equate each factor to zero and solve for l
l + 12 = 0 ⇒ l = - 12
l - 7 = 0 ⇒ l = 7
However, l > 0 ⇒ l = 7
The length = 7 feet and width = 7 + 5 = 12 feet