Question 896320
Let Jacobs age be 'J' years when Tony's age is as 4 times as Jacobs. Let Tony's age be 'T'.

J = 4T

The difference between Jacobs and Tonys ages doesn't change. (55 -7= 48)

J - T = 48

J = 48 + T

J = 4T

48 + T = 4T

48 = 3T

48/3 = T

T = 16

Now Tony is 7. In 9 years.. It will happen.