Question

Help me do this problem using the quadratic formula

Answer 1

It's a rectangle, so A= lw
$l = (x - 1)$
$w = ( x + 7)$
$A= (x - 1)(x + 7)$
*FOIL
$A = {x}^{2} + 6x - 7$
$500 = {x}^{2} + 6x - 7$
*Subtract 500 from both sides

$0 = {x}^{2} + 6x - 507$

*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