Question 1011920
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X=number of P20 bills; Y=number of P50 bills=2X-7
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P20(X)+P50(Y)=P1090
20x+50(2X-7)=1090
20X+100X-350=1090
120X=1440
X=12
ANSWER 1: There are twelve P20 bills.
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Y=2X-7=2(12)-7=24-7=17
ANSWER 2: There are seventeen P50 bills.
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CHECK:
P20(X)+P50(Y)=P1090
P20(12)+P50(17)=P1090
P240+P850=P1090
P1090=P1090