This is a substitution problem. Substitute the known value for "a" and "b" into the equation and solve:

Thus, the equation becomes 3(4) + 3(2) = 12 + 6 = 18

or by the distributive law 3(4) + 3(2) = 3(4 + 2) = 3(6) = 18

Thus, the equation becomes 3(4) + 3(2) = 12 + 6 = 18

or by the distributive law 3(4) + 3(2) = 3(4 + 2) = 3(6) = 18