Question 759058
Ann's age is seven-tenths of Bill's age. In 4 years ann's age will be eigth-elevenths of Bill's age. How old is Bill now?
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Equations:
a = (7/10)b
a+4 = (8/11)(b+4)
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Modify:
10a = 7b
11a + 44 = 8b+32
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Rearrange:
10a - 7b = 0
11a - 8b = -12
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Modify for elimination:
80a - 56b = 0
77a - 56b = -84
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Subtract and solve for "a":
3a = 84
a = 28
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Solve for "b":
7b = 10a
b = 10(28)/7
b = 40
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Cheers,
Stan H.
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