document.write( "Question 915878: A grocer wants to mix two kinds of coffee. One kind sells for $2.15 per pound and the other sells for 2.45 per pound. He wants to mix a total of 18 pounds and sell it for $2.30 per pound. How many pounds of each kind should he use in the new mix? \n" ); document.write( "
Algebra.Com's Answer #555801 by AlgebraLady88(44)![]() ![]() You can put this solution on YOUR website! This grocer is mixing two kinds of coffee. I always love the smell of coffee! \n" ); document.write( "We will say that x sells for $2.15 per pound and y sells for $2.45 per pound.\r \n" ); document.write( "\n" ); document.write( "Altogether there are 18 pounds of coffee he is selling. \n" ); document.write( "The algebraic equation would be x + y = 18\r \n" ); document.write( "\n" ); document.write( "At $2.30 per pound, he will make 18 * $2.30 = $ 41.40\r \n" ); document.write( "\n" ); document.write( "So, how many of the x and y kinds of coffee should he use to make the $2.30 per pound mixture which will net him $41.40? \n" ); document.write( "The algebraic equation would be 2.15x + 2.45y = 41.40\r \n" ); document.write( "\n" ); document.write( "We now have two equations :\r \n" ); document.write( "\n" ); document.write( "x+y = 18 \n" ); document.write( "2.15x + 2.45y = 41.40\r \n" ); document.write( "\n" ); document.write( "Substituting x= 18 -y in the second equation gives us\r \n" ); document.write( "\n" ); document.write( "2.15(18-y) + 2.45y = 41.40 \n" ); document.write( "38.70 - 2.15y + 2.45y = 41.40 \n" ); document.write( "38.70 + 0.3y = 41.40 \n" ); document.write( "0.3y = 41.40 - 38.70 \n" ); document.write( "0.3y= 2.70 \n" ); document.write( "y=9\r \n" ); document.write( "\n" ); document.write( "If y=9, then x= 9 as well. \r \n" ); document.write( "\n" ); document.write( "So, he will use 9 pounds of the $2.15 per/lb one and another 9 pounds of the $2.45per/lb one. \n" ); document.write( " |