document.write( "Question 980526: A person spent rs 564 buying pens and pencils. If the cost of each pen is rs 7 and each pencil is rs 3 and if the total number of things bought was 108, how many of each did he buy? \n" ); document.write( "
Algebra.Com's Answer #601645 by macston(5194)![]() ![]() You can put this solution on YOUR website! . \n" ); document.write( "X=number of pens; Y=number of pencils \n" ); document.write( ". \n" ); document.write( "X+Y=108 \n" ); document.write( "Y=108-X Use this to substitute for Y below. \n" ); document.write( ". \n" ); document.write( "rs7X+rs3Y=rs 564 Substitute for Y from above. \n" ); document.write( "rs7X+rs3(108-X)=rs 564 \n" ); document.write( "rs7X+rs324-rs3X=rs 564 subtract rs 324 from each side. \n" ); document.write( "rs4X=rs 240 Divide each side by rs 4. \n" ); document.write( "X=60 ANSWER 1: The person bought 60 pens. \n" ); document.write( ". \n" ); document.write( "Y=108-X \n" ); document.write( "Y=108-60 \n" ); document.write( "Y=48 ANSWER 2: The person bought 48 pencils. \n" ); document.write( ". \n" ); document.write( "CHECK: \n" ); document.write( "A person spent rs 564 buying pens and pencils. \n" ); document.write( "rs7X+rs3Y=rs 564 \n" ); document.write( "rs7(60)+rs3(48)=rs 564 \n" ); document.write( "rs 420+rs 144=rs 564 \n" ); document.write( "rs 564=rs564 \n" ); document.write( " \n" ); document.write( " |