document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=859689>Question 859689</A>: <I><SPAN STYLE=\"word-break: break-all;\"> -15x+7y=1 <BR>\n" );
document.write( "3x-y=1<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 #517902 by </B><A HREF=/tutors/aboutme.mpl?userid=JulietG><B>JulietG(1812)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=JulietG><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=JulietG><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=517902\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> -15x+7y=1 <BR>\n" );
document.write( "3x-y=1<BR>\n" );
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document.write( "In the second equation, isolate y by subtracting 3x from each side.<BR>\n" );
document.write( "-y = 1-3x<BR>\n" );
document.write( "Multiply each side by -1<BR>\n" );
document.write( "y = 3x-1<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Substitute the known value of Y into the first equation.<BR>\n" );
document.write( "-15x + 7(3x-1) = 1<BR>\n" );
document.write( "Distribute<BR>\n" );
document.write( "-15x +21x - 7 = 1<BR>\n" );
document.write( "Add Xs<BR>\n" );
document.write( "6x -7 = 1<BR>\n" );
document.write( "Add 7 to each side<BR>\n" );
document.write( "6x = 8<BR>\n" );
document.write( "Divide <BR>\n" );
document.write( "x = 8/6<BR>\n" );
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document.write( "If x = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2F6 ALIGN=MIDDLE  ALT=\"8%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then y=3x-1, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=24%2F6 ALIGN=MIDDLE  ALT=\"24%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" >-1, or 4-1, or 3.<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Let's put the numbers back into the first equation to see if it works.<BR>\n" );
document.write( "-15x+7y=1 <BR>\n" );
document.write( "-15(<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2F6 ALIGN=MIDDLE  ALT=\"8%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 7(3) = 1<BR>\n" );
document.write( "-<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=120%2F6 ALIGN=MIDDLE  ALT=\"120%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 21 = 1<BR>\n" );
document.write( "-20 + 21 = 1<BR>\n" );
document.write( "Success! </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );