Jill is 2 years older than Mike. in 5 years, 5 times Mike's age will be 4 times Jill's age. how old is Mike? Write an equation that models how old in years each of you will be, when your ages add up to 150 years old. For example, if x = your age and the eldest person was a year older than you, you would write their age as x + 1. Then the equation would be: x + (x+1) = 150.