Michael is three times as old as margaret, and in 6 years he will be twice as old as her. how old was michael when margaret was born?

12 years old

Step-by-step explanation:

m = Michael

a = Margaret

m = 3a

m+6 = 2(a+6)

m+6 = 2a+12

Two equations, two unknowns, so we can use substitution.

3a+6 = 2a+12

a+6 = 12

a = 6

Plug it back in.

m = 3(6)

m = 18

When Michael was 18, Margaret was 6. So when she was born (basically when she was 0) Michael was 18-6 = 12.