Question 314785
The sum of Jim's age and Mike's age is 52. Six years ago mike was four times as old as jim was. How old is each now?

Let x = jims age 
let y = mikes age 

1...x+y=52
15 years ago their ages were x-6 & y-6
y-6=4(x-6)
y-6=4x-24
2...y-4x=-18
Subtract eq2 fro eq1
..
x+y-y+4x=52-(-18)
5x=60
x= 12 years
y= 30 years