SOLUTION: I need an equation for: my age will be three times as old as my youngest son, 30,60. I think the answer is 15 and 45 but I do not know how to do the equation to get these figures.

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Question 736463: I need an equation for: my age will be three times as old as my youngest son, 30,60. I think the answer is 15 and 45 but I do not know how to do the equation to get these figures.
I was 30 when he was born so I need an equation which models how old in years each of us will be when I am three times as old as he.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = Son's age when Father is 3 times his age
Let +y+ = the Father's age then
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The difference in their ages will always be +30+ yrs, so
(1) +y+-+x+=+30+
I am also given:
(2) +y+=+3x+
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I can substitute (2) into (1)
(1) +3x+-x+=+30+
(1) +2x+=+30+
(1) +x+=+15+
and
(2) +y+=+3%2A15+
(2) +y+=+45+
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The son is 15 and the father is 45