document.write( "Question 465836: how many pounds of coffee worth 9 dollars a pound should be added to 30 pounds of coffee worth 3 dollars a pound to get a mixture worth 5 dollars a pound? \n" ); document.write( "

Algebra.Com's Answer #319213 by kingme18(98) $\"\"$ $\"About$

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x=number of pounds of $9 coffee\r
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\n" ); document.write( "\n" ); document.write( "I'm going to multiply each \"price per pound\" by \"number of pounds\". Note that our final mixture will have 30+x pounds, since we're adding x pounds in.\r
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\n" ); document.write( "\n" ); document.write( "$9/pound * x pounds + $3/pound * 30 pounds = $5/pound * (30 + x) pounds\r
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\n" ); document.write( "\n" ); document.write( " $\"9%2Ax%2B3%2A30=5%2A%2830%2Bx%29\"$ Simplify a bit: $\"9x%2B90=150%2B5x\"$ . Subtract 5x on both sides to bring all the x's together: $\"4x%2B90=150\"$ . Subtract 90 from both sides to get all the numbers together: $\"4x=60\"$ . Divide by 4 on both sides to finish getting x by itself: $\"x=15\"$ . Thus, you need to add 15 pounds of $9 coffee. \n" ); document.write( "

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