find the x-intercept 3x+2y=-6

The equation of the x axis is y=0.

Think about it and make sure you understand why this is so!

So you want to know where the line y=0 and the line 3x+2y=-6  cross over each other

Put y=0 inot your equations

3x+2*0=-6

3x+0=-6

3x=-6

x=-2  

or (-2,0)

Now you have your  x intercept  

3x+2y=-6

$$\boxed{y=0}$$

3x = -6 | :3

$$\boxed{x=-2}$$

x-intercept is -2