document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=122851>Question 122851</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The ratio of females to males in a school band is 7 to 4.  If three females and twelve males are absent from practice, the ratio of females to males is 5 to 2. How many members of the band attended practice? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #90220 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=90220\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The ratio of females to males in a school band is 7 to 4. If three females and twelve males are absent from practice, the ratio of females to males is 5 to 2. How many members of the band attended practice?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let x = boys<BR>\n" );
document.write( "Let y = girls;<BR>\n" );
document.write( ":<BR>\n" );
document.write( "It says,\"The ratio of females to males in a school band is 7 to 4.\" so we can say:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%2Fx ALIGN=MIDDLE  ALT=\"y%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7%2F4 ALIGN=MIDDLE  ALT=\"7%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cross multiply<BR>\n" );
document.write( "7x = 4y<BR>\n" );
document.write( "or<BR>\n" );
document.write( "7x - 4y = 0<BR>\n" );
document.write( ":<BR>\n" );
document.write( "If three females and twelve males are absent from practice, the ratio of females to males is 5 to 2. How many members of the band attended practice?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28y-3%29%29%2F%28%28x-12%29%29 ALIGN=MIDDLE  ALT=\"%28%28y-3%29%29%2F%28%28x-12%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F2 ALIGN=MIDDLE  ALT=\"5%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cross multiply<BR>\n" );
document.write( "5(x-12) = 2(y-3)<BR>\n" );
document.write( "5x - 60 = 2y - 6<BR>\n" );
document.write( "5x - 2y = +60 - 6<BR>\n" );
document.write( "5x - 2y = 54<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Use elimination; Mult the 2nd equation by 2; subtract the 1st equation<BR>\n" );
document.write( "10x - 4y = 108<BR>\n" );
document.write( " 7x - 4y =  0<BR>\n" );
document.write( "---------------- subtracting eliminates y<BR>\n" );
document.write( " 3x + 0y = 108<BR>\n" );
document.write( "x = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=108%2F3 ALIGN=MIDDLE  ALT=\"108%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x = 36 boys<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Find the girls<BR>\n" );
document.write( "7(36) = 4y<BR>\n" );
document.write( "252 = 4y<BR>\n" );
document.write( "y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=252%2F4 ALIGN=MIDDLE  ALT=\"252%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "y = 63 girls<BR>\n" );
document.write( ":<BR>\n" );
document.write( "But it asked how many attended practice:<BR>\n" );
document.write( "(36-12) + (63-3) = 84 kids<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Check:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=63%2F36 ALIGN=MIDDLE  ALT=\"63%2F36\"   DISABLED_style= \"max-width:90%; height:auto;\" > reduces to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7%2F4 ALIGN=MIDDLE  ALT=\"7%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60%2F24 ALIGN=MIDDLE  ALT=\"60%2F24\"   DISABLED_style= \"max-width:90%; height:auto;\" > reduces to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F2 ALIGN=MIDDLE  ALT=\"5%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );