SOLUTION: The sum of Steve and Tim is 72 years. In 12 years time Steve, the older person, will be 6 times the age that Tim was 21 years ago. 1.1) What are their present ages? 1.2) What w

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: The sum of Steve and Tim is 72 years. In 12 years time Steve, the older person, will be 6 times the age that Tim was 21 years ago. 1.1) What are their present ages? 1.2) What w      Log On

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Question 445517: The sum of Steve and Tim is 72 years. In 12 years time Steve, the older person, will be 6 times the age that Tim was 21 years ago.
1.1) What are their present ages?
1.2) What was the difference between their ages 15 years ago?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let s = Steve's age now
Let t = Tin's age now
given:
(1) +s+%2B+t+=+72+
(2) +s+%2B+12+=+6%2A%28+t+-+21%29+
-------------------
(1) +s+=+72+-+t+ )
By substitution:
(2) +72+-+t+%2B+12+=+6%2A%28+t+-+21%29+
(2) +72+-+t+%2B+12+=+6t+-+126+
(2) +7t+=+72+%2B+12+%2B+126+
(2) +7t+=+210+
+t+=+30+
and, since,
(1) +s+%2B+t+=+72+
(1) +s+%2B+30+=+72+
(1) +s+=+42+
-------------
(1.1) Steve is 42 and Tim is 30
(1.2) The difference in their ages never changes,
so, it was 12 years difference