document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1171641>Question 1171641</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 13-y=17 solve for y by dividing each side by -1 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #796544 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=796544\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 13 - y = 17<BR>\n" );
document.write( "divide both side by -1 to get:<BR>\n" );
document.write( "(13 - y) / -1 = 17 / -1<BR>\n" );
document.write( "simplify to get:<BR>\n" );
document.write( "-13 + y = -17<BR>\n" );
document.write( "add 13 to both sides of the equation to get:<BR>\n" );
document.write( "y = -17 + 13 = -4\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you did not divide each side by -1, you would have gotten:<BR>\n" );
document.write( "13 - y = 17<BR>\n" );
document.write( "add y to both sides of the equation and subtract 17 from both sides of the equation to get:<BR>\n" );
document.write( "13 - 17 = y<BR>\n" );
document.write( "solve for y to get:<BR>\n" );
document.write( "y = -4.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "it appears that the value of y is unchanged.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "in 13 - y = 17, replace y with - 4 to get:<BR>\n" );
document.write( "13 - -4 = 17 which becomes 13 + 4 = 17 which becomes 17 = 17.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "in -13 + y = -17, replace y with -4 to get:<BR>\n" );
document.write( "-13 - 4 = -17 which becomes -17 = -17\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the final value has been changed from 17 to -17, but the equality has been preserved.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "17 = 17 and -17 = -17.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "this is one of the rules of solving equations.<BR>\n" );
document.write( "if you multiply both sides of the equation by the same amount, the equality is preserved.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "since division is a form of multiplication, this applies to division as well.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "you could have divided by any number and the equality would have been preserved.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "for example, if you divided by -13, you would have gotten:\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "13 - y = 17 becomes:<BR>\n" );
document.write( "13/-13 - y/-13 = 17/-13<BR>\n" );
document.write( "you would add y/-13 to both sides of the equation and you would subtract 17/-13 from both sides of the equation to get:<BR>\n" );
document.write( "13/-13 - 17/-13 = y/-13<BR>\n" );
document.write( "you would multiply both sides of the equation by -13 to get:<BR>\n" );
document.write( "13 - 17 = y<BR>\n" );
document.write( "this would result in y = -4\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you solved the original equation without dividing by -13, you would have gotten.<BR>\n" );
document.write( "13 - y = 17<BR>\n" );
document.write( "add y to both sides and subtract 17 from both sides to get:<BR>\n" );
document.write( "13 - 17 = y<BR>\n" );
document.write( "solve for y to get:<BR>\n" );
document.write( "y = -4.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you replaced y with -4 in the original equation, you would have gotten:<BR>\n" );
document.write( "13 - -4 = 17 which would have resulted in:<BR>\n" );
document.write( "17 = 17.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you replaced y with -4 in the equations that was divided by -13 on both sides, you would have gotten:<BR>\n" );
document.write( "13/-13 - y/-13 = 17/-13 becomes:<BR>\n" );
document.write( "13/-13 - -4/-13 = 17/-13 which becomes:<BR>\n" );
document.write( "13/-13 + 4/-13 = 17/-3 which becomes:<BR>\n" );
document.write( "17/-13 = 17/-3<BR>\n" );
document.write( "the result was different but the equality was preserved.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );