document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=939394>Question 939394</A>: <I><SPAN STYLE=\"word-break: break-all;\"> At Scott's Laundromat, the washing machines accept only quarters and nickels. If Joe used 20 coins worth $2.60 to wash 4 loads, how many of each coin did he use?\r<BR>\n" );
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document.write( " 		A.	7 quarters and 13 nickels<BR>\n" );
document.write( " 		B.	6 quarters and 14 nickels<BR>\n" );
document.write( " 		C.	8 quarters and 12 nickels<BR>\n" );
document.write( " 		D.	9 quarters and 11 nickels </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #572392 by </B><A HREF=/tutors/aboutme.mpl?userid=srinivas.g><B>srinivas.g(540)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=srinivas.g><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=srinivas.g><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=572392\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1 nickle = 0.05 dollars<BR>\n" );
document.write( "1 quarter  =0.25 dollars<BR>\n" );
document.write( "let x be the no of nickles<BR>\n" );
document.write( "let y be the no of quarters<BR>\n" );
document.write( "total no of coins  =20<BR>\n" );
document.write( "  x+y = 20..............eq(1)<BR>\n" );
document.write( " total worth = $ 2.60<BR>\n" );
document.write( "   x*0.05+y*0.25 = $2.60 ..............eq(2)<BR>\n" );
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document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=linear_substitution.solver>SOLVE linear system by SUBSTITUTION</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>Solve:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+system%28+%0D%0A++++1%5Cx+%2B+1%5Cy+=+20%2C%0D%0A++++0.05%5Cx+%2B+0.25%5Cy+=+2.6+%29%0D%0A++ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >We'll use substitution. After moving 1*y to the right, we get:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2Ax+=+20+-+1%2Ay ALIGN=MIDDLE  ALT=\"1%2Ax+=+20+-+1%2Ay\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+20%2F1+-+1%2Ay%2F1 ALIGN=MIDDLE  ALT=\"x+=+20%2F1+-+1%2Ay%2F1\"   DISABLED_style= \"max-width:90%; height:auto;\" >. Substitute that<BR>\n" );
document.write( "  into another equation:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.05%2A%2820%2F1+-+1%2Ay%2F1%29+%2B+0.25%5Cy+=+2.6 ALIGN=MIDDLE  ALT=\"0.05%2A%2820%2F1+-+1%2Ay%2F1%29+%2B+0.25%5Cy+=+2.6\"   DISABLED_style= \"max-width:90%; height:auto;\" > and simplify: So, we know that y=8. Since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+20%2F1+-+1%2Ay%2F1 ALIGN=MIDDLE  ALT=\"x+=+20%2F1+-+1%2Ay%2F1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, x=12.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Answer: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28+x=12%2C+y=8+%29 ALIGN=MIDDLE  ALT=\"system%28+x=12%2C+y=8+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
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document.write( "Result : nickles  =12<BR>\n" );
document.write( "   quarters  = 8<BR>\n" );
document.write( " Option : C is the right choice </SPAN>\n" );
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