Answer
$\color{blue}{y=-3x-1}$
Work Step by Step
RECALL:
(1) The slope-intercept form of a line's equation is:
$y=mx+b$
where $m$ = slope and $b$ = y-intercept
(2) Parallel lines have the same (equal) slopes.
(3) Perpendicular lines have slopes whose product is $-1$ (negative reciprocals of each other).
The line is parallel to the line $y=-3x$ (whose slope is $-3$).
This means that the line we are looking for also has a slope of $-3$.
Thus, the tentative equation of the line is:
$y=-3x+b$
To find the value of $b$, substitute the x and y values of the given point to the tentative equation above to obtain:
$y=-3x+b
\\2=-3(-1)+b
\\2 = 3+b
\\2-3=b
\\-1=b$
Therefore, the equation of the line is:
$\color{blue}{y=-3x-1}$