The $x$-intercept is $3$. The $y$-intercept is $-9$. See the graph below.
Work Step by Step
In order to find the $x$-intercept, we have to plug $y=0$ into the equation, and the $x$-coordinate will give us the intercept itself. $y=3x-9$ $0=3x-9$ $x=3$ The same thing should be done for the $y$-intercept, however, here $x=0$ should be plugged into the equation. $y=3x-9$ $y=3(0)-9$ $y=-9$ The x-intercept is $3$ and the $y$-intercept is $-9$. Few other points that will help us plot the graph: If $x=2$ $y=3(2)-9=-3$ The point $(2,-3)$ is on the graph. If $x=4$ $y=3(4)-9=3$ The point $(4,3)$ is on the graph. If $x=5$ $y=3(5)-9=6$ The point $(5,6)$ is on the graph.