Graph the line with slope $-\frac{1}{3}$ passing through the point $(2,-1)$.

Step 1 ：We are given the slope of the line as $-\frac{1}{3}$ and the line passes through the point $(2,-1)$.

Step 2 ：The equation of a line in slope-intercept form is $y=mx+b$, where $m$ is the slope and $b$ is the y-intercept.

Step 3 ：We can substitute the given values into the equation to find the y-intercept $b$.

Step 4 ：Substituting $m=-\frac{1}{3}$ and $(x,y)=(2,-1)$ into the equation, we get $-1=-\frac{1}{3}\ast 2+b$.

Step 5 ：Solving for $b$, we get $b=-\frac{1}{3}$.

Step 6 ：Now that we have the y-intercept, we can write down the equation of the line.

Step 7 ：The equation of the line is $y=-\frac{1}{3}x-\frac{1}{3}$.

Step 8 ：$\boxed{{\displaystyle y=-\frac{1}{3}x-\frac{1}{3}}}$ is the final answer. The line can be graphed using this equation.