S = son's age, M = mother's age
S + 21 = M
5 * (S + 6) = M + 6
substitute for M:
5(S + 6) = S + 21 + 6
5S + 30 = S + 27
4S = -3
S = -3/4 = -9 months!
so the solution is:
All over the mother!
(i heard this as a joke, sorry i couldnt resist such cheap humor..) |