It's a rectangle, so A= lw
[tex]l = (x - 1)[/tex]
[tex]w = ( x + 7)[/tex]
[tex]A= (x - 1)(x + 7)[/tex]
*FOIL
[tex]A = {x}^{2} + 6x - 7[/tex]
[tex]500 = {x}^{2} + 6x - 7[/tex]
*Subtract 500 from both sides
[tex]0 = {x}^{2} + 6x - 507[/tex]
*Use Quadratic Formula
*x= was rounded
x=19.72 & x=-25.72
The negative one is not needed because you cannot have a negative length.
(19.72+7)×(19.72-1)=500.1984
