Area of a rectangle is length by width, width is x, length is x+8
x×(x+8)=240
x²+8x=240
x²+8x-240=0
Use the quadratic formula to solve
It is a distance so can't be negative, so the answer must be 12
x×(x+8)=240
x²+8x=240
x²+8x-240=0
Use the quadratic formula to solve
It is a distance so can't be negative, so the answer must be 12