document.write( "Question 255881: You buy 3 pencils and 1 pen for $1.75. You buy 2 pencils and 2 pens for $2.50. How much will 5 pencils cost? \n" ); document.write( "
Algebra.Com's Answer #188119 by checkley77(12844)![]() ![]() ![]() You can put this solution on YOUR website! 3x+1y=1.75 muliply by -2 & add. \n" ); document.write( "2x+2y=2.50 \n" ); document.write( "-6x-2y=-3.50 \n" ); document.write( "---------------- \n" ); document.write( "-4x=-1.00 \n" ); document.write( "x=-1.00/-4 \n" ); document.write( "x=$.25 cost of 1 pencil. \n" ); document.write( "3*.25+y=1.75 \n" ); document.write( ".75+y=1.75 \n" ); document.write( "y=1.75-.75 \n" ); document.write( "y=$1.00 cost of i pen. \n" ); document.write( "Proof: \n" ); document.write( "2*.25+2*1.00=2.50 \n" ); document.write( ".50+2.00=2.50 \n" ); document.write( "2.50=2.50 \n" ); document.write( "5*.25=$1.25 is the cost of 5 pencils. \n" ); document.write( " |