Age of father =44
Age of son =8
Let's think that after x years, father's age will be 4 times than that of son.
Ie,
After x years,
Father's age = 44+x
Age of son =8+x
Now
age of father=4× age of son
Ie,
44+x =4×(8+x)
44+x =32 +4x
44-32 =4x-x
12 =3x
Or,
x =12/3 =4
So after 4 years
age of father =44+4=48
Age of son =8+4=12
Ie,
44 =12×4
Or
Age of father is 4 times the age of son