document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=919866>Question 919866</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if 5x - 3y = 7 and -3x - 5y = 23 what is the value of x?\r<BR>\n" );
document.write( "\n" );
document.write( "my answer choices are:<BR>\n" );
document.write( "A. (-1,-4)<BR>\n" );
document.write( "B. (-4,-1) <BR>\n" );
document.write( "C. -4<BR>\n" );
document.write( "D. -1\r<BR>\n" );
document.write( "\n" );
document.write( "I tried using substitution but I do not get any of the above answers so I am stuck. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #558015 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=558015\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <TABLE  BORDER=1>\n" );
document.write( "\n" );
document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=linear_substitution.solver>SOLVE linear system by SUBSTITUTION</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>Solve:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+system%28+%0D%0A++++5%5Cx+%2B+-3%5Cy+=+7%2C%0D%0A++++-3%5Cx+%2B+-5%5Cy+=+23+%29%0D%0A++ ALIGN=MIDDLE  ALT=\"+system%28+%0D%0A++++5%5Cx+%2B+-3%5Cy+=+7%2C%0D%0A++++-3%5Cx+%2B+-5%5Cy+=+23+%29%0D%0A++\"   DISABLED_style= \"max-width:90%; height:auto;\" >We'll use substitution. After moving -3*y to the right, we get:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2Ax+=+7+-+-3%2Ay ALIGN=MIDDLE  ALT=\"5%2Ax+=+7+-+-3%2Ay\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+7%2F5+-+-3%2Ay%2F5 ALIGN=MIDDLE  ALT=\"x+=+7%2F5+-+-3%2Ay%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" >. Substitute that<BR>\n" );
document.write( "  into another equation:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-3%2A%287%2F5+-+-3%2Ay%2F5%29+%2B+-5%5Cy+=+23 ALIGN=MIDDLE  ALT=\"-3%2A%287%2F5+-+-3%2Ay%2F5%29+%2B+-5%5Cy+=+23\"   DISABLED_style= \"max-width:90%; height:auto;\" > and simplify: So, we know that y=-4. Since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+7%2F5+-+-3%2Ay%2F5 ALIGN=MIDDLE  ALT=\"x+=+7%2F5+-+-3%2Ay%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" >, x=-1.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Answer: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28+x=-1%2C+y=-4+%29 ALIGN=MIDDLE  ALT=\"system%28+x=-1%2C+y=-4+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "  </TD></TR>\n" );
document.write( "</TABLE>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );