document.write( "Question 1004583: A person wishes to mix coffee worth $12 per lb with coffee worth $6 per lb to get 90 lb of a mixture worth $8 per lb. How many pounds of the $12 and the $6 coffees will be needed? \r
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Algebra.Com's Answer #621018 by addingup(3677)![]() ![]() You can put this solution on YOUR website! x+y= 90 \n" ); document.write( "Subtract x on both sides: \n" ); document.write( "y= 90-x In the next equation we will substitute y with this value: \n" ); document.write( "---------------------- \n" ); document.write( "We want to get 90lbs of coffee at $8 per pound, we want 90*8= 720: \n" ); document.write( "12x+6y= 8(90) In this equation, substitute the value of y with 90-y: \n" ); document.write( "-------------- \n" ); document.write( "12x+6(90-x)= 720 \n" ); document.write( "12x+540-6x= 720 \n" ); document.write( "6x= 180 \n" ); document.write( "x= 30 \n" ); document.write( "You need 30lb of $12 coffee with 90-30= 60 lbs of the $6 coffee \n" ); document.write( " |