the length of the rectangle is 10ft
Step-by-step explanation:
let the length = x
width = x - 4
area = length X width
so, according to the problem
x(x-4) = 60
or, [tex]x^{2}[/tex] - 4x = 60
or, [tex]x^{2}[/tex] -4x -60 = 0
or, [tex]x^{2}[/tex] - 10x + 6x -60 = 0
or, x(x-10) +6(x-10) =0
or, (x-10)(x+6) = 0
x = 10 ( x= -6 for length this value is not possible)
so length is 10ft
width = 10 - 4 = 6ft