x+y=50 1

3(x+y)= 5+y ^ 2

Convert 2 to 3x-Y=-10 3.

From 1, x = 50-y 4.

Bring 4 into 3,3 (50-y)-y =-10.

Y = 40

Substitute Y=40 into 1 and X+40=50.

X= 10

A: Tintin is now 10 years old, and his father is now 40 years old.