#### Answer

$x^{2}+x-20=0$

#### Work Step by Step

$x=-5$ or $ x=4\qquad$....get $0$'s on one side.
$x+5=0$ or $ x-4=0\qquad$....Use the principle of zero products (multiplying). The solutions of this equation are $-5$ and $4$.
$(x+5)(x-4)=0\qquad$...use the FOIL method to multiply.
$ x^{2}-4x+5x-20=0\qquad$...combine like terms.
$x^{2}+x-20=0$