Respuesta :
Honestly trial and error is the simplest way to go. As you can easily find out 6 times 9 makes 54. Otherwise, check out the link below for a full agrebraic solution.
https://photomath.net/s/90QPe
https://photomath.net/s/90QPe

Let the width of the rectangle be x
width = x
length = x+3
Area = width times length
Area = x(x+3)
= x^2 + 3x
Area = 54
implies that
x^2 + 3x = 54
x^2 +3x - 54=0
x^2 +9x - 6x - 54 = 0
x(x+9)-6(x+9)=0
(x+9)(x-6)=0
x=6
The width is 6 feet and the length is 3 plus 6 or 9.
width = x
length = x+3
Area = width times length
Area = x(x+3)
= x^2 + 3x
Area = 54
implies that
x^2 + 3x = 54
x^2 +3x - 54=0
x^2 +9x - 6x - 54 = 0
x(x+9)-6(x+9)=0
(x+9)(x-6)=0
x=6
The width is 6 feet and the length is 3 plus 6 or 9.