Question 1122802
My younger sister's age today is 3 times what it will be 3 years from now minus 3 times what her age was 3 years ago. find her present age 
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Equation:
S = 3[S+3]-3[S-3]
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Divide thru by 3 to get:
S/3 = S+3-S+3
S/3 = 6
Sister's age is 18 yrs
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Cheers,
Stan H.
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