Answer
$\color{blue}{y=-3x+3}$
Work Step by Step
RECALL:
The slope-intercept form of a line's equation is:
$y=mx+b$
where $m$=slope and $b$ = y-intercept.
The given line has:
slope =$-3$
y-intercept = $3$
Substituting these values into the slope-intercept form above gives:
$\color{blue}{y=-3x+3}$