When my father was 31 I was 8. Now he is twice as old as me. How old am I?
(31+x) = 2 ( 8 + x) Given where x is a number of years ....you age is 8+x
31+ x = 16 + 2x
x = 15 your age = 8 + 15 = 23 y/o
Correct!