document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=948328>Question 948328</A>: <I><SPAN STYLE=\"word-break: break-all;\"> PhotoLab charges $9.00 for processing a 24-exposure roll of film and $12.00 for processing a 36-exposure roll.  After their class trip, Mr. Renkens' 8th grade class sent 22 rolls of film to be developed and paid $219 for processing.<BR>\n" );
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document.write( "A.  Write a system of equations to describe the situation.<BR>\n" );
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document.write( "B.  Find the number of rolls of 24-exposure and the number of 36-exposure film that were processed using either elimination or substitution.  Make sure to show your work for full credit. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #578822 by </B><A HREF=/tutors/aboutme.mpl?userid=macston><B>macston(5194)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=macston><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=macston><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=578822\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> X=number of 24-exposure rolls;  Y=number of 36 exposure rolls<BR>\n" );
document.write( "SECTION A: System of Equations\r<BR>\n" );
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document.write( "X+Y=22<BR>\n" );
document.write( "$9.00X+$12.00Y=$219\r<BR>\n" );
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document.write( "SECTION B: Solution\r<BR>\n" );
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document.write( "METHOD 1: SUBSTITUTION<BR>\n" );
document.write( "Solve the first equation for X<BR>\n" );
document.write( "X+Y=22 Subtract Y from each side<BR>\n" );
document.write( "X=22-Y Now substitute for X in the second equation.<BR>\n" );
document.write( "$9.00X+$12.00Y=$219<BR>\n" );
document.write( "$9.00(22-Y)+$12.00Y=$219<BR>\n" );
document.write( "$198-$9.00Y+$12.00Y=$219<BR>\n" );
document.write( "$198+$3.00Y=$219 Subtract $198 from each side.<BR>\n" );
document.write( "$3.00Y=$21 Divide each side by $3.00<BR>\n" );
document.write( "Y=7 ANSWER 1:The number of 36-exposure rolls is 7.<BR>\n" );
document.write( "Back solve in one of the equations to find X (First equation is easiest)<BR>\n" );
document.write( "X+Y=22<BR>\n" );
document.write( "X+7=22 Subtract 7 from each side.<BR>\n" );
document.write( "X=15 ANSWER 2: There were 15 rolls of 24-exposure film.<BR>\n" );
document.write( "CHECK <BR>\n" );
document.write( "It is best to use the equation you did not use to back solve, so use equation 2<BR>\n" );
document.write( "$9.00(X)+$12.00(Y)=$219<BR>\n" );
document.write( "$9.00(15)+$12.00(7)=$219<BR>\n" );
document.write( "$135+$84=$219<BR>\n" );
document.write( "$219=$219\r<BR>\n" );
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document.write( "METHOD 2: ELIMINATION<BR>\n" );
document.write( "X+Y=22 <BR>\n" );
document.write( "$9.00(X)+$12.00(Y)=$219 Multiply first equation by $9.00 <BR>\n" );
document.write( "$9.00(X)+$9.00(Y)=$198 Subtract this from second equation to eliminate X.<BR>\n" );
document.write( "$3.00(Y)=$21 Divide each side by $3.00<BR>\n" );
document.write( "Y=7 ANSWER 1: The number of 36-exposure rolls is 7.<BR>\n" );
document.write( "From this point, the same as above. <BR>\n" );
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