Question 1150389
let f = father's present age
let y = your present age
:
Write an equation for each statement, simplify each equation
:
Twelve years ago my father was twice as old as I was,
f - 12 = 2(y-12)
f - 12 = 2y - 24
f = 2y - 24 + 12
f = 2y - 12

 and three years ago our combined age was 108.
(f-3) + (y-3) = 108
f + y - 6 = 108
f + y = 108 + 6
f + y = 114
Replace f with (2y-12) from the 1st equation
(2y-12) + y = 114
3y = 114 + 12
3y = 126
y = 126/3
y = 42 is your age
then
f = 2(42) - 12
f = 84 - 12
f = 72 is father's age
:
:
Confirm that in statement:
"twelve years ago my father was twice as old as I was,"
72 - 12 = 2(42-12)
60 = 2(30)