document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=744227>Question 744227</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 7x + 5y =77\r<BR>\n" );
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document.write( "3x- 4y = -10 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #454578 by </B><A HREF=/tutors/aboutme.mpl?userid=Chipmonkcheeks><B>Chipmonkcheeks(3)</B></A><img src=\"/images/stars/iconNewId_16x16.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Chipmonkcheeks><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=454578\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Call 7x + 5y = 77 equation I, and called 3x - 4y = -10 equation II.<BR>\n" );
document.write( "Then from equation I, if you -5y from both sides of the equation:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7x+=+77+-+5y ALIGN=MIDDLE  ALT=\"7x+=+77+-+5y\"   DISABLED_style= \"max-width:90%; height:auto;\" > ,<BR>\n" );
document.write( "Then dividing both sides by 7:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+11+-+%285%2F7%29y ALIGN=MIDDLE  ALT=\"x+=+11+-+%285%2F7%29y\"   DISABLED_style= \"max-width:90%; height:auto;\" > .\r<BR>\n" );
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document.write( "We can then substitute this expression for x into equation II. This gives us:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2811+-+%285%2F7%29y%29+-+4y+=+-10 ALIGN=MIDDLE  ALT=\"3%2811+-+%285%2F7%29y%29+-+4y+=+-10\"   DISABLED_style= \"max-width:90%; height:auto;\" > .\r<BR>\n" );
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document.write( "Expanding the brackets:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=33+-+%2815%2F7%29y+-+4y+=+-10 ALIGN=MIDDLE  ALT=\"33+-+%2815%2F7%29y+-+4y+=+-10\"   DISABLED_style= \"max-width:90%; height:auto;\" >, which is equivalent to,\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=43+=+%2843%2F7%29y ALIGN=MIDDLE  ALT=\"43+=+%2843%2F7%29y\"   DISABLED_style= \"max-width:90%; height:auto;\" >, which gives us that\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+7 ALIGN=MIDDLE  ALT=\"y+=+7\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "Then substituting this back into our expression for x gives us:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+11+-+%285%2F7%29%2A7 ALIGN=MIDDLE  ALT=\"x+=+11+-+%285%2F7%29%2A7\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <BR>\n" );
document.write( "which give us that <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+6 ALIGN=MIDDLE  ALT=\"x+=+6\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Best to check these answers by substituting them back into the original equations. </SPAN>\n" );
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