College Algebra (10th Edition)

$n=-2$
$3+2n=4n+7$ $\longrightarrow$addition property of equality $3+2n-2n-7=4n+7-2n-7$ $\longrightarrow$combine like terms $-4=2n$ $\longrightarrow$multiplication property of equality $-4\div2=2n\div2$ $\longrightarrow$simplify $-2=n$