document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=293431>Question 293431</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I missed one class due to illness and now I am very lost. I think I need help determining which formulas to use for this word problem. I have plotted a few different ways and not sure if it makes sense.  Here is the question:<BR>\n" );
document.write( "Irvin's parents allow him to use the family car provided he pay for the gas, which averages $1.60 per gallon.  The car averages 20 miles per gallon. To help Irvin earn gas money, this parents pay him $10 a week to do chores. Determine and then plot a weekly savings equation for Irvin that represents earnings minus money spent on gas. Write a physical interpretation for both intercepts of the savings equation.\r<BR>\n" );
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document.write( "I have tried having x=miles and y=allowance. I got a slope of 12.5 (which was cents per gallon of gas) I would appreciate any help on this. <BR>\n" );
document.write( " Thank you so much.\r<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 #211831 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=211831\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Where is the equation?<BR>\n" );
document.write( "What are you talking about with 12.5 cents per gallon? We are told it is $1.60 a gallon not $.125 per gallon. <BR>\n" );
document.write( "What did you do with x=miles and y = allowance?\r<BR>\n" );
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document.write( "We are told \" Determine and then plot a weekly savings equation for Irvin that represents earnings minus money spent on gas. Write a physical interpretation for both intercepts of the savings equation.\"<BR>\n" );
document.write( "Each week he is given $10 but he spends 1.6 per gallon <BR>\n" );
document.write( "x=gallons<BR>\n" );
document.write( "y= savings<BR>\n" );
document.write( "earnings =$10<BR>\n" );
document.write( "minus gas expense<BR>\n" );
document.write( "y=10-(1.60*x)<BR>\n" );
document.write( "The problem told you how to set it up.<BR>\n" );
document.write( "\"plot a weekly savings equation for Irvin that represents earnings minus money spent on gas.\"<BR>\n" );
document.write( "The y intercept is the earnings. If he doesn't buy any gas (x) he can save $10<BR>\n" );
document.write( "So if x=0 then  y=10\r<BR>\n" );
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document.write( "If he has no savings (y=0) then the cost of gas used up all his allowance <BR>\n" );
document.write( "So if y=0 then 1.60*x=10 which is the x intercept of x=10/1.60=10/1.6=100/16 </SPAN>\n" );
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