Answer
$y-9=−\dfrac{1}{3}(x+2)$
Work Step by Step
RECALL:
The point-slope form of a line's equation is $y−y_1=m(x−x_1)$ where m=slope and $(x_1, y_1)$ is a point on the line.
The given line has a slope of $−\dfrac{1}{3}$ (so m=$−\frac{1}{3}$) and contains the point $(−2, 9)$ (so $x_1=−2$, $y_1=9$).
Thus, the equation of the line in point-slope form is:
$y−9=−\dfrac{1}{3}(x−(-2))
\\y-9=−\dfrac{1}{3}(x+2)$
