high shoool algebra
posted by roy on .
Joy is 20 years older than Bob. Three years ago, Joy was 5 times as old as Bob. How old are they now?

ages now:
Bob  x
Joy x+20
ages 3 years ago:
Bob  x3
Joy  x+20  3 = x+17
at that time, Joy was 5 times as old as Bob
> x+17 = 5(x3)
x+17 = 5x  15
4x =  32
x = 33/4 = 8
Bob is now 8 years, Joy is 28
Three years ago, Bob was 5 ,and Joy was 25
Was she 5 times as old as Bob, YES!! 
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