Question 491647
The sum of Mrs. Black's age and her daughter's age is 56 years. In 8 years, Mrs. Black will be twice as old as her daughter. How old is her daughter now? 
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Equations:
m + d = 56
(m+8) = 2(d+8)
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Substitute for "m" and solve for "d":
(56-d+8) = 2d + 16
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64 - d = 2d + 16
3d = 48
d = 16 (the daughter is 16 yrs old)
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Cheers,
Stan H.
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