document.write( "Question 355647: Mary and Jane shop at an office supplies store. Mary spends $20 on 10 pens and
\n" ); document.write( "10 notebooks. Jane spends $15 on 5 pens and 8 notebooks. Find the prices of the
\n" ); document.write( "stationery. \n" ); document.write( "
Algebra.Com's Answer #253943 by mananth(16946)\"\" \"About 
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let price of pen be $x
\n" ); document.write( "price of notebook be $y/10
\n" ); document.write( "...
\n" ); document.write( "10x+10y=20
\n" ); document.write( "x+y=2.......................1
\n" ); document.write( "5x+8y=15....................2
\n" ); document.write( "multiply equation 1 by -5 and add it to equation2
\n" ); document.write( "-5x-5y=-10
\n" ); document.write( "add to 2
\n" ); document.write( "8y-5y=15-10
\n" ); document.write( "3y=5
\n" ); document.write( "/3
\n" ); document.write( "y = 5/3
\n" ); document.write( "...
\n" ); document.write( "plug value of y in equation 1
\n" ); document.write( "x+5/3 = 2
\n" ); document.write( "(3x+5)/3=2
\n" ); document.write( "3x+5 =6
\n" ); document.write( "3x=6-5
\n" ); document.write( "3x=1
\n" ); document.write( "x= 0.33
\n" ); document.write( "...
\n" ); document.write( "Pen costs 33 cents
\n" ); document.write( "notebook costs $1.67
\n" ); document.write( "...
\n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( "
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