document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=968792>Question 968792</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi appreciated tutors,<BR>\n" );
document.write( "I have been studying linear systems and have a good understanding of solving them but this word problem is driving me crazy. Here is the problem verbatim;\r<BR>\n" );
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document.write( "The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost per gallon of each type of gasoline?\r<BR>\n" );
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document.write( "I tried to set up the problem like this:<BR>\n" );
document.write( "x+y=25<BR>\n" );
document.write( "10x+15y=32.75<BR>\n" );
document.write( "I figured the .20 would be added to the final \"y\" value. <BR>\n" );
document.write( "The way it comes out when I work the equations by trying to use substitution is a negative number. This is one indication I am working it incorrectly. Please show me a verbal model and work the equations and explain how to include the\".20\". THANKS very much!<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 #591949 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=591949\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost per gallon of each type of gasoline? <BR>\n" );
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document.write( "10R + 15P = 3275<BR>\n" );
document.write( "P = R + 20<BR>\n" );
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document.write( "Sub for P<BR>\n" );
document.write( "10R + 15*(R+20) = 3275<BR>\n" );
document.write( "25R + 300 = 3275<BR>\n" );
document.write( "R = 119<BR>\n" );
document.write( "P = 139 </SPAN>\n" );
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