Alexander B. answered • 05/16/18

Advanced Math and Science Tutoring and Test Prep online (SAT, ACT)

First person X is 50 years old, the second one is Y=70 years old. To find the ages (X and Y), solve system of equations:

X/Y = 5/7

(X-18)/(Y-18) = 8/13

Simplify:

7X - 5 Y = 0

13X - 8Y = 90

Finally: X = 50, Y=70 (the answer)