## Prealgebra (7th Edition)

$y=5$
$4(y+1)-3=21$ $\longrightarrow$ apply distributive property $4y+4-3=21$ $\longrightarrow$ simplify $4y+1=21$ $\longrightarrow$ subtract 1 from each side $4y+1-1=21-1$ $\longrightarrow$ simplify $4y=20$ $\longrightarrow$ divide each side by 4 $4y\div4=20\div4$ $\longrightarrow$ simplify $y=5$