Solve using substitution technique; - 3x+y=2, 12x-4y=-8

The first equation is easier to solve for y than is the 2nd: y = 3x+2. Subst. 3x+2 for y in the second equation:

12x - 4 (3x+2) = - 8

Expanding, 12x = 12x - 8 = - 8

This is always true, no matter the value of x. Thus, the solution set is "all real numbers."