SOLUTION: John is 30 years old when cindy is m years old. How old will John be when cindy is 20 years old?

Algebra ->  Equations -> SOLUTION: John is 30 years old when cindy is m years old. How old will John be when cindy is 20 years old?      Log On


   

Question 1037776: John is 30 years old when cindy is m years old. How old will John be when cindy is 20 years old?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Cindy becomes +20+ yrs old
+20+-+m+ yrs from now
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John will be +30+%2B+20+-+m+ at that time
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check:
suppose +m+=+15+
Cindy will be +20+ in +5+ yrs
John will be +35+ in +5+ yrs
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+30+%2B+20+-+m+=+30+%2B+20+-15+
+30+%2B+20+-+m+=+35+
OK