Question 1010168: Mary is fifteen years older than her sister Jane. Six years ago, Mary was six times as old as Jane. Find their present ages. thanks and I really need this asap...
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! x represents jane's age today.
mary's age today is x + 15.
6 years ago, jane was x - 6 years old.
6 years ago, mary was x + 15 - 6 = x + 9 years old.
6 years ago, mary was 6 times as old as jane.
x + 9 = 6 * (x - 6)
simplify to get x + 9 = 6x - 36
subtract x from both sides of this equation and add 36 to both sides of this equation to get:
x + 9 - x + 36 = 6x - 36 - x + 36
combine like terms to get 45 = 5x
divide both sides of this equation by 5 to get 9 = x
jane is 9 years old today.
mary is 9 + 15 = 24 years old today.
that's your solution.
6 years ago, jane was 3.
6 years ago, mary was 18
18 = 6 * 3
solution is confirmed as good.
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