document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1154197>Question 1154197</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A chemical company makes two brands of antifreeze. The first brand is 45% pure antifreeze, and the second brand is 85%  pure antifreeze. In order to obtain 40 gallons of a mixture that contains 75%  pure antifreeze, how many gallons of each brand of antifreeze must be used? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #776589 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=776589\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+ ALIGN=MIDDLE  ALT=\"+a+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = gallons of 45% antifreeze needed<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+ ALIGN=MIDDLE  ALT=\"+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = gallons of 85% antifreeze needed<BR>\n" );
document.write( "----------------------------------------------------<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+%2B+b+=+40+ ALIGN=MIDDLE  ALT=\"+a+%2B+b+=+40+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+.45a+%2B+.85b+%29+%2F+40+=+.75+ ALIGN=MIDDLE  ALT=\"+%28+.45a+%2B+.85b+%29+%2F+40+=+.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+.45a+%2B+.85b+=+30+ ALIGN=MIDDLE  ALT=\"+.45a+%2B+.85b+=+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+45a+%2B+85b+=+3000+ ALIGN=MIDDLE  ALT=\"+45a+%2B+85b+=+3000+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+17b+=+600+ ALIGN=MIDDLE  ALT=\"+9a+%2B+17b+=+600+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------------------<BR>\n" );
document.write( "Multiply both sides of (1) by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9 ALIGN=MIDDLE  ALT=\"9\"   DISABLED_style= \"max-width:90%; height:auto;\" > and<BR>\n" );
document.write( "subtract (1) from (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9a+%2B+17b+=+600+ ALIGN=MIDDLE  ALT=\"+9a+%2B+17b+=+600+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-9a+-+9b+=+-360+ ALIGN=MIDDLE  ALT=\"+-9a+-+9b+=+-360+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+8b+=+240+ ALIGN=MIDDLE  ALT=\"+8b+=+240+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+30+ ALIGN=MIDDLE  ALT=\"+b+=+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+%2B+30+=+40+ ALIGN=MIDDLE  ALT=\"+a+%2B+30+=+40+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+10+ ALIGN=MIDDLE  ALT=\"+a+=+10+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "10 gallons of 45% antifreeze are needed<BR>\n" );
document.write( "30 gallons of 85% antifreeze are needed<BR>\n" );
document.write( "-----------------------------------------------<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+.45a+%2B+.85b+%29+%2F+40+=+.75+ ALIGN=MIDDLE  ALT=\"+%28+.45a+%2B+.85b+%29+%2F+40+=+.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+.45%2A10+%2B+.85%2A30+%29+%2F+40+=+.75+ ALIGN=MIDDLE  ALT=\"+%28+.45%2A10+%2B+.85%2A30+%29+%2F+40+=+.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+4.5+%2B+25.5+%29+%2F+40+=+.75+ ALIGN=MIDDLE  ALT=\"+%28+4.5+%2B+25.5+%29+%2F+40+=+.75+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4.5+%2B+25.5+=+30+ ALIGN=MIDDLE  ALT=\"+4.5+%2B+25.5+=+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+30+=+30+ ALIGN=MIDDLE  ALT=\"+30+=+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );