You can set the value of the opposite variable equal to 0 to find the intercept of the other variable.
Let's find the x intercept first.
4x - 9(0) = 30
4x = 30
Divide both sides by 4.
The x intercept is 7.5
Now the y intercept.
4(0) - 9y = 30
-9y = 30
Divide both sides by -9.
The y intercept is -3.33