Luis is 4 years older than laura. In 7 years the sum of their ages will be 72. How old is laura?

Answer 1

M=4+W

M+7 + W+7 = 72

4+W + 7 + W+7 = 72

2W = 72-7-7-4 = 54

W = 54/2 = 27 years old for Laura

Luis is 31 years old

in 7 years they'll be 34 and 38, which sum to 72