7th Grade Math
posted by Missy .
Mayla's mother is 3 times as old as Mayla. Eight years ago her mother was 7 times as old as Mayla. What are their ages now?
A: Mayla 10; her mother 30
B: Mayla 12; her mother 36
C: Mayla 13; her mother 39
D: Mayla 14; her mother 42
I think the answer is B. But I want to know is there an equation.

MM=3M
MM8=7(M8)
subtracting the equations...
8=3M7M+56
4M=48
and you are correct.