document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=152634>Question 152634</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0321233832/algebrahomeworkh>elementary and intermediate algebra concepts and applications</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Can somebody please help me I forgot how to do these problems?\r<BR>\n" );
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document.write( "Translate the following into a system of equations, then solve it:<BR>\n" );
document.write( "     A customer walks into an electronics store and buys five MP3 players and 	eight sets of headphones, paying $840.  A second customer buys three 	MP3 players and four sets of headphones, and pays $480.  How much 	does an MP3 player cost?  How much does a set of headphones cost?<BR>\n" );
document.write( "(i) What are the x-intercept and y-intercept of a linear equation?  <BR>\n" );
document.write( "(ii) What are their coordinates on a graph?  <BR>\n" );
document.write( "(iii) How can they be used to graph a line?  <BR>\n" );
document.write( "(iv) Demonstrate by determining the intercepts of \"14x + 7y = 21\".  <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #112190 by </B><A HREF=/tutors/aboutme.mpl?userid=Fombitz><B>Fombitz(32388)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Fombitz><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=Fombitz><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=112190\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let M be the price of an MP3 player, H the price of the headphones.<BR>\n" );
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document.write( "First customer: 5 MP3 players, 8 headphones, $840<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5M%2B8H=840 ALIGN=MIDDLE  ALT=\"5M%2B8H=840\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Second customer: 3 MP3 players, 4 headphones, $480<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3M%2B4H=480 ALIGN=MIDDLE  ALT=\"3M%2B4H=480\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Now you have two equations in two unknowns, M and H.<BR>\n" );
document.write( "1.<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5M%2B8H=840 ALIGN=MIDDLE  ALT=\"5M%2B8H=840\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "2.<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3M%2B4H=480 ALIGN=MIDDLE  ALT=\"3M%2B4H=480\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Use 1 to come up with an expression for M in terms of H.<BR>\n" );
document.write( "1.<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5M%2B8H=840 ALIGN=MIDDLE  ALT=\"5M%2B8H=840\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5M=840-8H ALIGN=MIDDLE  ALT=\"5M=840-8H\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=%281%2F5%29%28840-8H%29 ALIGN=MIDDLE  ALT=\"M=%281%2F5%29%28840-8H%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute this expression into 2 and solve for H. <BR>\n" );
document.write( "2.<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3M%2B4H=480 ALIGN=MIDDLE  ALT=\"3M%2B4H=480\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%281%2F5%29%28840-8H%29%2B4H=480 ALIGN=MIDDLE  ALT=\"3%281%2F5%29%28840-8H%29%2B4H=480\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%28840-8H%29%2B20H=2400 ALIGN=MIDDLE  ALT=\"3%28840-8H%29%2B20H=2400\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2520-24H%2B20H=2400 ALIGN=MIDDLE  ALT=\"2520-24H%2B20H=2400\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-4H=-120 ALIGN=MIDDLE  ALT=\"-4H=-120\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=H=30 ALIGN=MIDDLE  ALT=\"H=30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "From above,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=%281%2F5%29%28840-8H%29 ALIGN=MIDDLE  ALT=\"M=%281%2F5%29%28840-8H%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=%281%2F5%29%28840-8%2830%29%29 ALIGN=MIDDLE  ALT=\"M=%281%2F5%29%28840-8%2830%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=%281%2F5%29%28840-240%29 ALIGN=MIDDLE  ALT=\"M=%281%2F5%29%28840-240%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=%281%2F5%29%28600%29 ALIGN=MIDDLE  ALT=\"M=%281%2F5%29%28600%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=M=120 ALIGN=MIDDLE  ALT=\"M=120\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "And now for something completely different.<BR>\n" );
document.write( "X intercept: where the line crosses the X axis.<BR>\n" );
document.write( "Coordinates are (<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5Bi%5D ALIGN=MIDDLE  ALT=\"x%5Bi%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0 ALIGN=MIDDLE  ALT=\"0\"   DISABLED_style= \"max-width:90%; height:auto;\" >).<BR>\n" );
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document.write( "Y intercept: where the line crosses the Y axis.<BR>\n" );
document.write( "Coordinates are (<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0 ALIGN=MIDDLE  ALT=\"0\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%5Bi%5D ALIGN=MIDDLE  ALT=\"y%5Bi%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >).<BR>\n" );
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document.write( "You only need two points to graph a line.<BR>\n" );
document.write( "If you have both the the x and y intercepts, those are two points you could use to graph the line. <BR>\n" );
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document.write( "For the x intercept, set y=0, solve for x.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14x%2B7y=21 ALIGN=MIDDLE  ALT=\"14x%2B7y=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14x%2B7%280%29=21 ALIGN=MIDDLE  ALT=\"14x%2B7%280%29=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14x=21 ALIGN=MIDDLE  ALT=\"14x=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=3%2F2 ALIGN=MIDDLE  ALT=\"x=3%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(3/2,0)<BR>\n" );
document.write( "Graph it. <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28+300%2C+300%2C+-5%2C+5%2C+-5%2C+5%2Cgrid%28+1+%29%2Cgreen%28circle%28+1.5%2C+0%2C+.15+%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "For the y intercept, set x=0, solve for y.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14x%2B7y=21 ALIGN=MIDDLE  ALT=\"14x%2B7y=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14%280%29%2B7y=21 ALIGN=MIDDLE  ALT=\"14%280%29%2B7y=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y=21 ALIGN=MIDDLE  ALT=\"7y=21\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=3 ALIGN=MIDDLE  ALT=\"y=3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(0,3)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28+300%2C+300%2C+-5%2C+5%2C+-5%2C+5%2Cgrid%28+1+%29%2Cgreen%28circle%280%2C3%2C.15%29%29%2Cgreen%28circle%28+1.5%2C+0%2C+.15+%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "The last step is to draw a line connecting those two points.<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28+300%2C+300%2C+-5%2C+5%2C+-5%2C+5%2Cgrid%28+1+%29%2Cgreen%28line%28-6%2C15%2C6%2C-9%29%29%2Cgreen%28circle%280%2C3%2C.15%29%29%2Cgreen%28circle%28+1.5%2C+0%2C+.15+%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );