document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=478318>Question 478318</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help? I don;t understand the process of this. \r<BR>\n" );
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document.write( "The following problem can be modeled with a linear equation. Analyze the problem and identify what quantities the variables x and y represent. The information provided in the problem is adequate to determine a point and a slope or two points on the line.\r<BR>\n" );
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document.write( "Robinson Wholesale Company paid $1380 for 500 items. Later they bought 800 items for $1710. Assume that the cost is a linear function of the number of items. Write the equation. (Let y represent the amount paid and x represent the number of items purchased.)\r<BR>\n" );
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document.write( "The answer is y = 1.1x + 830 I don't have a clue how to get this though. \r<BR>\n" );
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document.write( "???<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 #327749 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=327749\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Robinson Wholesale Company paid $1380 for 500 items.<BR>\n" );
document.write( " Later they bought 800 items for $1710.<BR>\n" );
document.write( " Assume that the cost is a linear function of the number of items.<BR>\n" );
document.write( " Write the equation.<BR>\n" );
document.write( "(Let y represent the amount paid and x represent the number of items purchased.)<BR>\n" );
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document.write( "Assign the xy values as follows<BR>\n" );
document.write( "x1=500; y1=1380<BR>\n" );
document.write( "x2=800; y2=1710<BR>\n" );
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document.write( "Find the slope using the equation; m=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28y2-y1%29%2F%28x2-x1%29 ALIGN=MIDDLE  ALT=\"%28y2-y1%29%2F%28x2-x1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "m = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281710-1380%29%2F%28800-500%29 ALIGN=MIDDLE  ALT=\"%281710-1380%29%2F%28800-500%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "m = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=330%2F300 ALIGN=MIDDLE  ALT=\"330%2F300\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "m = 1.1 is the slope<BR>\n" );
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document.write( "Use the point/slope formula create the equation: y - y1 = m(x-x1)<BR>\n" );
document.write( "y - 1380 = 1.1(x - 500)<BR>\n" );
document.write( "y - 1380 = 1.1x - 550<BR>\n" );
document.write( "y = 1.1x - 550 + 1380<BR>\n" );
document.write( "y = 1.1x + 830<BR>\n" );
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document.write( "Now do you see how they came up with this??<BR>\n" );
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