document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=628750>Question 628750</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A 150-lb person who runs at 6mph for 1hr burns about 720 calories. The same person, walking at 2 mph for 90 min, burns about 120 calories. Suppose a 150-lb person runs at 6 mph for 75 min. How  far would the person have to walk at 2 mph in order to burn the same numberof calories as burned when running? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #395819 by </B><A HREF=/tutors/aboutme.mpl?userid=graphmatics><B>graphmatics(170)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=graphmatics><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=graphmatics><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=395819\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x be the number of calories generated per pound.\n" );
document.write( "let y be the calories generated per minute of speed. Then\n" );
document.write( "150x+6*60y=720\n" );
document.write( "150x+2*90y=120<BR>\n" );
document.write( "150x+360y=720\n" );
document.write( "150x+180y=120\n" );
document.write( "we solve this system of equations\n" );
document.write( "<TABLE  BORDER=1>\n" );
document.write( "\n" );
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.solver>Linear System solver (using determinant)</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++++150%5Cx+%2B+360%5Cy+=+720%2C%0D%0A++++150%5Cx+%2B+180%5Cy+=+120+%29%0D%0A++ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Any system of equations:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+system%28+%0D%0A++++a%5B11%5D%2Ax+%2B+a%5B12%5D%2Ay+=+b%5B1%5D%2C%0D%0A++++a%5B21%5D%2Ax+%2B+a%5B22%5D%2Ay+=+b%5B2%5D%29%0D%0A++ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  has solution<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+system%28+%0D%0A++++x+=+%28b%5B1%5D%2Aa%5B22%5D+-+b%5B2%5D%2Aa%5B12%5D%29%2F%28a%5B11%5D%2Aa%5B22%5D-a%5B21%5D%2Aa%5B12%5D%29%2C%0D%0A++++y+=+%28a%5B11%5D%2Ab%5B2%5D+-+a%5B21%5D%2Ab%5B1%5D%29%2F%28a%5B11%5D%2Aa%5B22%5D-a%5B21%5D%2Aa%5B12%5D%29%0D%0A++++%29%0D%0A++ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  or<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+system%28+%0D%0A++++++x+=+%28720%2A180+-+120%2A360%29%2F%28150%2A180-150%2A360%29+=+-3.2%2C%0D%0A++++++y+=+%28150%2A120+-+150%2A720%29%2F%28150%2A180-150%2A360%29+=+3.33333333333333%0D%0A++++%29%0D%0A++ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  (x=-3.2, y=3.33333333333333}<BR>\n" );
document.write( "  </TD></TR>\n" );
document.write( "</TABLE><BR>\n" );
document.write( "So x=3.2 and y=3.333333.\n" );
document.write( "For a 150 pound person running at 6 mph for 75 minutes the number of calories generated is\n" );
document.write( "150*3.2+6*75*3.333333=1978.5\n" );
document.write( "To find the distance covered at 2 mph we need to find the number of minutes required to generate 1978.5 calories so if z is the number of minutes\n" );
document.write( "150*3.2+2*z*3.333333=1978.5. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );