document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1123708>Question 1123708</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A school has just purchased new computer equiptment for $25,000.00. The graph shows the desciption of the equiptment over 5 years. The point (0, 25,000) represents the purchase price and the point (5,0) represents when the equiptment will be replaced. Write a linear equation in slope-intercept form that models the value of the equiptment, y, x years after purchase. Use the model to predict the value of the equiptment after 2 year?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #740090 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=740090\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the point (0,2500) says the value of y = 25000 when the value of x is equal to 0.\r<BR>\n" );
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document.write( "x represents the number of years since the computer was purchased.<BR>\n" );
document.write( "y represents the depreciated value of the computer after x years.\r<BR>\n" );
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document.write( "the point (5,0) says the value of y = 25000 when the value of x is 5.\r<BR>\n" );
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document.write( "this means the depreciated value of the computer is 0 after 5 years.\r<BR>\n" );
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document.write( "with straight line depreciation, the same value is subtracted from the computer every year the computer is in use.\r<BR>\n" );
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document.write( "the computer goes from 25,000 to 0 in 5 years.<BR>\n" );
document.write( "25,000 / 5 = a depreciation value of 5000 each year.\r<BR>\n" );
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document.write( "the slope intercept form of a linear equation is y = mx + b\r<BR>\n" );
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document.write( "m is the slope<BR>\n" );
document.write( "b is the y-intercept.\r<BR>\n" );
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document.write( "if the value of the computer goes down every year, than the slope is -5000.\r<BR>\n" );
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document.write( "the slope is the change in the value of y for every change in the value of x.\r<BR>\n" );
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document.write( "a slope of -5000 is the same as a slope of -5000 / 1\r<BR>\n" );
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document.write( "that says the value of y goes down 5000 for every increase of 1 in the value of x.\r<BR>\n" );
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document.write( "the euatin becomes y = -5000 * x + b\r<BR>\n" );
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document.write( "to solve for b, you need a point on the line.\r<BR>\n" );
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document.write( "(0,25000) is one point on the line.<BR>\n" );
document.write( "(5,0) is the other point on the line.\r<BR>\n" );
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document.write( "i'll use (5,0).<BR>\n" );
document.write( "you can use (0,25000) yourself to see that you'll get the same value of b.\r<BR>\n" );
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document.write( "when you use the point (5,0), y = -5000 * x + b becomes 0 = -5000 * 5 + b\r<BR>\n" );
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document.write( "you replace x with 5 and you replace y with 0 to solve for b.\r<BR>\n" );
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document.write( "0 = -5000 * 5 + b becomes 0 = -25000 + b\r<BR>\n" );
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document.write( "solve for b to get b = 25000.\r<BR>\n" );
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document.write( "the equation becomes y = -5000 * x + 25000\r<BR>\n" );
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document.write( "this is your linear equation in slope intercept form.\r<BR>\n" );
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document.write( "at the end of 2 years, the equation becomes y = -5000 * 2 + 25,000, which results in y = 15,000\r<BR>\n" );
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document.write( "the depreciated value of the computer is 15,000 after 2 years.\r<BR>\n" );
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document.write( "the equation can be graphed as shown below:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/092001.jpg\" alt=\"$$$\" >\r<BR>\n" );
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document.write( "the red line is the line of the equation of y = -5000 * x + 25000.\r<BR>\n" );
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document.write( "the vertical dashed lines are just there to allow me to show the intersection points of the depreciated value of the computer after x years.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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