Let x = Ben's age
Let y = Ishaan's age.
2 years ago: y + 12 = x
3 years ago 4y = x. Set the equations equal to each other.
y + 12 = 4y. Subtract y from each side.
12 = 3y. Divide each side by 3.
4 = y. Plug this value into any of the original equations.
4 + 12 = 16.
Ben is 16 years old and Ishaan is 4 years old.