## Introductory Algebra for College Students (7th Edition)

$y=4$
$y(y+8)=16(y-1)\qquad$...apply the distributive rule: $m(n\pm c)=mn\pm mc$ $y^{2}+8y=16y-16\qquad$...add $(-16y+16)$ to both sides $y^{2}-8y+16=0\qquad$...recognize a perfect square trinomial. $(A\pm B)^{2}=A^{2}\pm 2AB+B^{2}$ $(y-4)^{2}=0$ $(y-4)(y-4)=0\qquad$...apply the principle of zero products. $y=4$ Type the equation into a graphing utility and see that the graph intercepts the x-axis at $4$.