Mike is four years older than his brother, Andrew. If five times Andrew's age is equal to three times Mike's age, how old is Mike

I think at least one person's name is missing from this problem. However, if I understand correctly

Andrew's age = x

Mike's age = (x + 4)

5x = 3 (x + 4)

5x = 3x + 12

2x = 12

x = 6, so Andrew is 6 years old and Mike is (6 + 4) = 10 years old