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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-> 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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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}
