Answer:
Maggie is 13 years old.
Explanation:
1M + 1B = 62
rearrange to get:
1B = 62 - 1M
4M - 3 = 1B
substitute B with 62 - 1M so there is only one variable. this gives:
4M - 3 = 62 - 1M
Get all the variables on one side:
4M + 1M - 3 = 62
Get all non variables on the other side:
4M + 1M = 62 + 3
simplify:
5M = 65
Divide both sides by 5 to get the M by itself:
M = 13.
BONUS:
M + B = 62
B = 49
So her brother is 49 years old.
Maggie is 13 years old.