Answer:
width = 8 feet and length = 12 feet
Step-by-step explanation:
Let the width be w then the length = 3w - 12 ( 12 less than 3 times the width )
The area (A) of a rectangle is
A = length × width, that is
w(3w - 12) = 96 ← area of floor
3w² - 12w = 96 ( subtract 96 from both sides )
3w² - 12w - 96 = 0 ← in standard form for a quadratic equation
Divide all terms by 3
w² - 4w - 32 = 0
Consider the product of the factors of the constant term ( - 32) which sum to give the coefficient of the w- term (- 4)
The factors are - 8 and + 4, since
- 8 × 4 = - 32 and - 8 + 4 = - 4, hence
(w - 8)(w + 4) = 0
Equate each factor to zero and solve for w
w - 8 = 0 ⇒ w = 8
w + 4 = 0 ⇒ w = - 4
However, w > 0 ⇒ w = 8
Hence width = 8 feet
length = 3w - 12 = (3 × 8) - 12 = 24 - 12 = 12 feet
