Answer
12 inches and 7 inches
Work Step by Step
area = 84
$a = (x+3)(x-2)$
$84 = x*x+x*(-2)+3*x+3*(-2)$
$84 = x^2-2x+3x-6$
$84=x^2+x-6$
$90 = x^2+x$
$x^2+x-90=0$
$x^2+x-90$
$x^2+10x-9x-90$
$x(x+10)-9(x+10)$
$(x-9)(x+10) = 0$
$x-9=0$
$x=9$
$x+10=0$
$x=-10$ (we can't have a negative length, so this answer doesn't work)
$x=9$
$(x+3)(x-2)$
$(9+3)(9-2)$
$(12)(7)$
