factor

or x=6

(x+10)(x-6) = 0

${x}^{2}+4x=60$

Two ways to do it

Way One: factoring

${x}^{2}+4x-60=0$

$(x+10)(x-6)=0$

$x=-10$ or $x=6$

Way Two: completing the square

${x}^{2}+4x+4=64$

${(x+2)}^{2}=64$

$x+2=±8$

$x=-2±8$

$x=-10$​ or