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

$z=-3$
$3z=-2z-15$ First add 2z to both sides. $3z+2z=-15$ $5z=-15$ Then divide both sides by 5. 5z$\div$5=-15$\div$5 $z=-3$ Check the answer. 3(-3)=-2(-3)-15 -9=6-15 -9=-9