Answer:
let f = your father's age today.
let s = your age today.
f = 4s
this means your father's age is 4 times your age today.
f = s + 27
this means your father is 27 years older than you.
replace f in the second equation with 4s from the first equation to get:
4s = s + 27
subtract s from both sides of the equation to get 3s = 27
solve for s to get s = 9
that's your age today.
f = 4s = 36
that's your father's age today.
you were both 14 years ago.
your father was 36 - 27 = 9 years old at the time.
solution looks good.
your father is 36 and you are 9 today.