document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=198309>Question 198309</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A driver notices that after driving 100 miles there are 12.8 gallons of fuel left in her car's tank.  After driving 300 miles she notices that there are only 6.4 gallons left in the tank.\r<BR>\n" );
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document.write( "A) Determine a linear function that will give the number of gallons left in the tank as a function of the number of miles driven.\r<BR>\n" );
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document.write( "B)Based on this model how much  fuel does the tank hold? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #148785 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=148785\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The 1st step is to decide what goes on the x-axis<BR>\n" );
document.write( "and what goes on the y-axis.<BR>\n" );
document.write( "Q: Does miles driven determine how much is left<BR>\n" );
document.write( "in the tank?<BR>\n" );
document.write( "Does how much is left in the tank determine the<BR>\n" );
document.write( "miles?<BR>\n" );
document.write( "The 1st statement is true, so y-axis is the gallons<BR>\n" );
document.write( "left in tank and x-axis is the miles driven<BR>\n" );
document.write( "(x causes y)<BR>\n" );
document.write( "I'm given 2 points, (x,y):<BR>\n" );
document.write( "(100,12.8)<BR>\n" );
document.write( "(300,6.4)<BR>\n" );
document.write( "The formula is:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y+-+6.4%29%2F%28x+-+300%29+=+%2812.8+-+6.4%29%2F%28100+-+300%29 ALIGN=MIDDLE  ALT=\"%28y+-+6.4%29%2F%28x+-+300%29+=+%2812.8+-+6.4%29%2F%28100+-+300%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y+-+6.4%29%2F%28x+-+300%29+=+6.4%2F-200 ALIGN=MIDDLE  ALT=\"%28y+-+6.4%29%2F%28x+-+300%29+=+6.4%2F-200\"   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=-200%2A%28x+-+300%29 ALIGN=MIDDLE  ALT=\"-200%2A%28x+-+300%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y+-+6.4%29%2A%28-200%29+=+6.4%2A%28x+-+300%29 ALIGN=MIDDLE  ALT=\"%28y+-+6.4%29%2A%28-200%29+=+6.4%2A%28x+-+300%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-200y+%2B+1280+=+6.4x+-+1920 ALIGN=MIDDLE  ALT=\"-200y+%2B+1280+=+6.4x+-+1920\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=200y+=+-6.4x+%2B+3200 ALIGN=MIDDLE  ALT=\"200y+=+-6.4x+%2B+3200\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-.032x+%2B+16 ALIGN=MIDDLE  ALT=\"y+=+-.032x+%2B+16\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "I checked the points (100,12.8) and (300,6.4) <BR>\n" );
document.write( "They are on this line<BR>\n" );
document.write( "Here's a plot:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+400%2C+400%2C+-50%2C+550%2C+-2%2C+20%2C+-.032x+%2B+16%29+ ALIGN=MIDDLE  ALT=\"+graph%28+400%2C+400%2C+-50%2C+550%2C+-2%2C+20%2C+-.032x+%2B+16%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "If the driver drives 0 miles (uses no gas), there are<BR>\n" );
document.write( "16 gallons in the tank (full)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-.032%2A0+%2B+16 ALIGN=MIDDLE  ALT=\"y+=+-.032%2A0+%2B+16\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+16 ALIGN=MIDDLE  ALT=\"y+=+16\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );