Answer
$x=4$
Work Step by Step
$-3(x-6)+13=20-1$ $\longrightarrow$distributive property
$-3x+18+13=20-1$ $\longrightarrow$combine like terms
$-3x+31=19$ $\longrightarrow$addition property
$-3x+31-31=19-31$ $\longrightarrow$combine like terms
$-3x=-12$ $\longrightarrow$multiplication property
$-3x\div-3=-12\div-3$ $\longrightarrow$simplify
$x=4$