document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=456897>Question 456897</A>: <I><SPAN STYLE=\"word-break: break-all;\"> At the car wash there is a flat fee for the first 8 minutes. Sally was there for 12 mins and cost her $5. John was there for 17 mins and cost him $6.25. Write a equation and find the cost of the flat fee and cost per minute. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #313615 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=313615\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> At the car wash there is a flat fee for the first 8 minutes.<BR>\n" );
document.write( " Sally was there for 12 mins and cost her $5.<BR>\n" );
document.write( " John was there for 17 mins and cost him $6.25.<BR>\n" );
document.write( " Write a equation and find the cost of the flat fee and cost per minute.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let f = flat fee for the 1st 8 min<BR>\n" );
document.write( "Let a = cost for each additional min<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Two equations:<BR>\n" );
document.write( ":<BR>\n" );
document.write( "\"Sally was there for 12 mins and cost her $5.\"<BR>\n" );
document.write( "a(12-8) + f = $5<BR>\n" );
document.write( "4a + f = $5<BR>\n" );
document.write( ":<BR>\n" );
document.write( "\" John was there for 17 mins and cost him $6.25.\"<BR>\n" );
document.write( "a(17-8) + f = $6.25<BR>\n" );
document.write( "9a + f = 6.25<BR>\n" );
document.write( ":<BR>\n" );
document.write( "We can use elimination here, subtract the 1st equation from the 2nd<BR>\n" );
document.write( "9a + f = 6.25<BR>\n" );
document.write( "4a + f = 5.00<BR>\n" );
document.write( "-----------------subtraction eliminates f find a<BR>\n" );
document.write( "5a = 1.25<BR>\n" );
document.write( "a = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1.25%2F5 ALIGN=MIDDLE  ALT=\"1.25%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a = .25 for each additional min<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Find f using the 1st equation<BR>\n" );
document.write( "4(.25) + f = 5<BR>\n" );
document.write( "1.00 + f = 5<BR>\n" );
document.write( "f = 5 - 1<BR>\n" );
document.write( "f = $4 is the flat fee for the 1st 8 min<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Check our solutions in the 2nd equation<BR>\n" );
document.write( "9(.25) + 4.00 = 6.25\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );