let x be the father's age and y be the son's age..
x= 3times the age of son
x=3y
father's age{x) + son's age (y) = 44
now we have these
x=3y
x+y =44
substitute x with 3y for the 2nd equation
so we now we have 3y+y=44
u can solve this from here.
after getting the y(the son's age) you can find the dad's (x) age by myltiply the son's age by 3 ..GOODLUCK :)