Question 187480
A carpenter goes to a hardware store to buy a specific number of pounds of nails for his business.
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Let # of pounds be "x"
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 The first store he enters sells his favorite-sized nails at nine cents per pound. At this price, the carpenter realizes that he would be short $7.15 if he tried to buy the nails.
Let "y" be the money he has.
9x = y + 715
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The carpenter goes to a competing hardware store and finds the nails sell for six cents per pound. He realizes that after paying for the nails, he would have $2.45 left over.
6x = y -245
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How many pounds of nails is he trying to buy?
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Rearrange the equations:
y= 9x - 715
y = 6x + 245
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Substitute to solve for "x":
9x - 715 = 6x + 245
3x= 960
x = 320 lbs (# of pounds he is trying to buy)
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Cheers,
Stan H.