Answer
$x=\dfrac{1}{3}y-\dfrac{7}{3}$
Work Step by Step
Using the properties of equality, in terms of $
x
,$ the given expression, $
-3x+y=7
,$ is equivalent to
\begin{array}{l}\require{cancel}
-3x=-y+7
\\\\
x=\dfrac{-1}{-3}y+\dfrac{7}{-3}
\\\\
x=\dfrac{1}{3}y-\dfrac{7}{3}
.\end{array}