Algebra: A Combined Approach (4th Edition)

$y=2.0$
$0.8y+0.2(y-1)=1.8$ $0.8y+0.2y-0.2=1.8$ $1.0y-0.2=1.8$ Adding $0.2$ to both sides, $1.0y-0.2+0.2=1.8+0.2$ $1.0y=2.0$ Divide both sides by $1.0$: $y=2.0$.