solve your equation for y in terms of x
2x+3y=-12
3y=-2x-12
y=-2/3x-4
The basic linear equation is: y=mx+b, where m is the slope, b is the y-intercept.
So, the slope in your equation is -2/3, the y-intercept is -4.
Do you know how to graph a line using the slope and y-intercept?