Hi
John is twenty years younger than Amy
Let x and (x-20)represent Amy's and John's age NOW
Question states*** in 5 yrs...
(x-20) + 5 = (1/2)(x+5)
Solving for x
1/2x = 5/2 + 15
x = 5 + 30
x = 35, Amy's age now. John is now 15. (35-15)
CHECKING our Answer***in 5 yrs...
20 = (1/2)40