What is the answer

Question

Michael is 3 times as old as Brandon. 18 years ago, Michael was 9 times as old as Brandon.

Answer 1

Let m = Michael's age

Let b = Brandon's age

m = 3b

m - 18 = 9(b - 18)

Substitute 3b for m in the 2nd equation and solve for b.

3b - 18 = 9(b - 18)

3b - 18 = 9b - 162

-3b. -3b

-18 = 6b - 162

+162. +162

144 = 6b

÷6. ÷6

b = 24 yrs old

And m = 3b, so m = 3(24), m = 72 yrs old