<PRE><B>Question 148933</B>
Walt made an extra $9000 last year from a part-time job. he invested part of the money at 9% and the rest at 8%. he made a total of $770 in interest. How much was invested at 8%?
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Quantity Equation: x + y = 9000
Interest Equation: 0.09x + 0.08y = 770
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Modify the equations 
9x + 9y = 81000
9x + 8y = 77000
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Subtract 2nd from 1st to get:
y = 4000 (Amt. invested at 8%)
Since x+y = 9000, x = 5000 (Amt. invested at 9%)
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Cheers,
Stan H.
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