document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230685>Question 230685</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Carole's car averages 13.4 miles per gallon in city driving and 25.7 miles per gallon in highway driving. If she drove a total of 522.8 miles on 28 gallons of gas, then how many of the gallons were used for city driving? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #170864 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=170864\">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;\" > = miles of hwy driving<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;\" > = miles of city driving<BR>\n" );
document.write( "given:<BR>\n" );
document.write( "Total gas used = 28 gallons <BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%2F25.7+%2B+b%2F13.4+=+28 ALIGN=MIDDLE  ALT=\"a%2F25.7+%2B+b%2F13.4+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+%2B+b+=+522.8 ALIGN=MIDDLE  ALT=\"a+%2B+b+=+522.8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "This is 2 equations with 2 unknowns, so<BR>\n" );
document.write( "it's solvable<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%2F25.7+%2B+b%2F13.4+=+28 ALIGN=MIDDLE  ALT=\"a%2F25.7+%2B+b%2F13.4+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=25.7%2A13.4+=+344.38 ALIGN=MIDDLE  ALT=\"25.7%2A13.4+=+344.38\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13.4a+%2B+25.7b+=+28%2A344.38 ALIGN=MIDDLE  ALT=\"13.4a+%2B+25.7b+=+28%2A344.38\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13.4a+%2B+25.7b+=+9642.64 ALIGN=MIDDLE  ALT=\"13.4a+%2B+25.7b+=+9642.64\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides of (2) by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13.4 ALIGN=MIDDLE  ALT=\"13.4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and subtract from (1)<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13.4a+%2B+25.7b+=+9642.64 ALIGN=MIDDLE  ALT=\"13.4a+%2B+25.7b+=+9642.64\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-13.4a+-+13.4b+=+-7005.52 ALIGN=MIDDLE  ALT=\"-13.4a+-+13.4b+=+-7005.52\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12.3b+=+2637.12 ALIGN=MIDDLE  ALT=\"12.3b+=+2637.12\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b+=+214.4 ALIGN=MIDDLE  ALT=\"b+=+214.4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "214.4 gallons were used for city driving<BR>\n" );
document.write( "check answer:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+%2B+b+=+522.8 ALIGN=MIDDLE  ALT=\"a+%2B+b+=+522.8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+%2B+214.4+=+522.8 ALIGN=MIDDLE  ALT=\"a+%2B+214.4+=+522.8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+=+522.8+-+214.4 ALIGN=MIDDLE  ALT=\"a+=+522.8+-+214.4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a+=+308.4 ALIGN=MIDDLE  ALT=\"a+=+308.4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%2F25.7+%2B+b%2F13.4+=+28 ALIGN=MIDDLE  ALT=\"a%2F25.7+%2B+b%2F13.4+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=308.4%2F25.7+%2B+214.4%2F13.4+=+28 ALIGN=MIDDLE  ALT=\"308.4%2F25.7+%2B+214.4%2F13.4+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=12+%2B+16+=+28 ALIGN=MIDDLE  ALT=\"12+%2B+16+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=28+=+28 ALIGN=MIDDLE  ALT=\"28+=+28\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK\r<BR>\n" );
document.write( "\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );