Question 252437: two years ago, Anton was three times as old as his sister, Nathalie. In 4 years, he will be only twice his sister's age. Find their present ages?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Let their present ages by a & n
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Write an equation for each statement:
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two years ago, Anton was three times as old as his sister, Nathalie.
a - 2 = 3(n-2)
a - 2 = 3n - 6
a = 3n - 6 + 2
a = 3n - 4
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In 4 years, he will be only twice his sister's age.
a + 4 = 2(n + 4)
a + 4 = 2n + 8
a = 2n + 8 - 4
a = 2n + 4
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Find their present ages?
Replace a with the 1st equation, find n
3n - 4 = 2n + 4
3n - 2n = 4 + 4
n = 8
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I'll let you find a
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