SOLUTION: barry is 8 years older than his sister. in 3 years he will be twice as old as sue was 5 years ago. find their ages now.

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Question 421091: barry is 8 years older than his sister. in 3 years he will be twice as old as sue was 5 years ago. find their ages now.
Answer by algebrahouse.com(1659) About Me  (Show Source):
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"barry is 8 years older than his sister. in 3 years he will be twice as old as sue was 5 years ago. find their ages now."

x = sister's age now
x + 8 = Barry's age now

x + 3 = sister in 3 years
x + 11 = Barry in 3 years

x + 11 = 2(x - 5) {in 3 years, he will be twice as old as her, 5 yrs ago}
x + 11 = 2x - 10 {used distributive property}
11 = x - 10 {subtracted x from both sides}
x = 21 {added 10 to both sides}
x + 8 = 29 {substituted 21, in for x, into x + 8}

Barry is 29 and Sue is 21
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