To find the x-intercept you must make y=0
3x+2y=12 - substitute 0 for y
3x+2(0)=12 - multiply 2 and 0
3x+0=12 - add zero
3x=12 - divide by 3
x=4
To find the y-intercept you must make x=0
3x+2y=12 - substitute 0 for x
3(0)+2y=12 - multiply 3 and 0
0+2y=12 - add 0 and 2y
2y=12 - divide by 2
y=6