document.write( "Question 442915: This is a substitution/elimination problem. A coffee counter charges 9.00 per pound for Kenyan French Roast coffee and 8.00 per pound for Sumatran coffee. How much of each type should be used to make a 20 pound blend that sells for 8.40 a pound? \n" ); document.write( "

Algebra.Com's Answer #305524 by nerdybill(7384) $\"\"$ $\"About$

You can put this solution on YOUR website!
A coffee counter charges 9.00 per pound for Kenyan French Roast coffee and 8.00 per pound for Sumatran coffee. How much of each type should be used to make a 20 pound blend that sells for 8.40 a pound?
\n" ); document.write( "Let x = amount(lbs) of kenyan coffee
\n" ); document.write( "and y = amount(lbs) of Sumatra coffee
\n" ); document.write( ".
\n" ); document.write( "x+y = 20 (equation 1)
\n" ); document.write( ".
\n" ); document.write( "9x + 8y = 8.40(20) (equation 2)
\n" ); document.write( ".
\n" ); document.write( "solve equation 1 for y:
\n" ); document.write( "y = 20-x
\n" ); document.write( "substitute into equation 2:
\n" ); document.write( "9x + 8(20-x) = 8.40(20)
\n" ); document.write( "9x + 160-8x = 168
\n" ); document.write( "x + 160 = 168
\n" ); document.write( "x = 8 pounds (Kenyan)
\n" ); document.write( ".
\n" ); document.write( "Sumatra:
\n" ); document.write( "x+y = 20
\n" ); document.write( "8+y = 20
\n" ); document.write( "y = 12 pounds
\n" ); document.write( " \n" ); document.write( "

\n" );