Equation 2 can be rearranged: y=(12-2x)/3=-2x/3+4. Now we have two equations in standard linear form so they can be plotted on the same graph. Use the intercepts of each line to make it easy to draw two lines that intersect at a point which has coordinates equal to the solution to the system of equations.
Intercepts for equation 1: y-int is -1 and x-int is 1. Draw a line through (0,-1) and (1,0).
Intercepts for equation 2: y-int is 4 and x-int is 6. Draw a line through (0,4) and (6,0).
The lines cross when -2x/3+4=x-1; 5=5x/3, so x=3. When x=3, y=2. So the point of intersection should be (3,2).