SOLUTION: 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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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?
Found 2 solutions by lwsshak3, stanbon:
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
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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let x=Bill's age now
7x/10=Ann's age
In 4 yrs:
x+4=Bill's age
7x/10+4=Ann's age
%287x%2F10%2B4%29=8%28x%2B4%29%2F11
LCD=110
%2877x%2B440%29=80%28x%2B4%29
77x+440=80x+320
3x=120
x=40
Bill's age now=40

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
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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