document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=827125>Question 827125</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 8x-y=4 and 5x+3y=17 solving by substitution. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #498487 by </B><A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><B>TimothyLamb(4379)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><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=TimothyLamb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=498487\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> ---<BR>\n" );
document.write( "8x-y=4<BR>\n" );
document.write( "x+3y=17<BR>\n" );
document.write( "---<BR>\n" );
document.write( "copy and paste the above linear system in standard form into this matrix-method solver:<BR>\n" );
document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "solution by matrix-method:<BR>\n" );
document.write( "x = 1.16<BR>\n" );
document.write( "y = 5.28<BR>\n" );
document.write( "---<BR>\n" );
document.write( "system matrix<BR>\n" );
document.write( "8 -1<BR>\n" );
document.write( "1 3<BR>\n" );
document.write( "---<BR>\n" );
document.write( "inverse of system matrix<BR>\n" );
document.write( "0.12 0.04<BR>\n" );
document.write( "-0.04 0.32<BR>\n" );
document.write( "---<BR>\n" );
document.write( "determinant of system matrix = 25<BR>\n" );
document.write( "---<BR>\n" );
document.write( "now by substitution-method:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "8x - y = 4<BR>\n" );
document.write( "y = 8x - 4<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x + 3y = 17<BR>\n" );
document.write( "x + 3(8x - 4) = 17<BR>\n" );
document.write( "x + 24x - 12 = 17<BR>\n" );
document.write( "25x = 29<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x = 29/25<BR>\n" );
document.write( "x = 1.16<BR>\n" );
document.write( "---<BR>\n" );
document.write( "y = 8x - 4<BR>\n" );
document.write( "y = 8*(29/25) - 4<BR>\n" );
document.write( "---<BR>\n" );
document.write( "y = 5.28<BR>\n" );
document.write( "---<BR>\n" );
document.write( "solution by substitution-method:<BR>\n" );
document.write( "x = 1.16<BR>\n" );
document.write( "y = 5.28<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the two methods agree.<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve and graph linear equations:<BR>\n" );
document.write( "https://sooeet.com/math/linear-equation-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve quadratic equations, quadratic formula:<BR>\n" );
document.write( "https://sooeet.com/math/quadratic-formula-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve systems of linear equations up to 6-equations 6-variables:<BR>\n" );
document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );