Answer: width = 6 feet
Length = 15 feet
Step-by-step explanation:
Let L represent the length of the rectangle.
Let W represent the width of the rectangle.
A rectangle has a length that is three feet more than twice its width. It means that
L = 2W + 3
Area = length × width
If the area of the rectangle is 90 square feet, it means that
W(2W + 3) = 90
2W² + 3W = 90
2W² + 3W - 90 = 0
2W² + 15W - 12W - 90 = 0
W(2W + 15) - 6(2W + 15) = 0
W - 6 = 0 or 2W + 15 = 0
W = 6 or W = - 15/2
Since the width cannot be negative, then
W = 6
L = 2W + 3 = 2 × 6 + 3
L = 15
