document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=773737>Question 773737</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Is this how to reduce this expression?\r<BR>\n" );
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document.write( " 5a-{-[(-3a+2b)-4b]+[-7a-(a-b)]-3b}\r<BR>\n" );
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document.write( "=5a-{-[-3a+2b-4b]+[-7a-a+b]-3b}\r<BR>\n" );
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document.write( "=5a-{3a-2b+4b+7a+a-b-3b}\r<BR>\n" );
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document.write( "=5a-3a+2b-4b-7a-a+b+3b\r<BR>\n" );
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document.write( "=-6a+2b\r<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 #471869 by </B><A HREF=/tutors/aboutme.mpl?userid=KMST><B>KMST(5328)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=KMST><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=KMST><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=471869\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 5a-{-[(-3a+2b)-4b]+[-7a-(a-b)]-3b} <BR>\n" );
document.write( "=5a-{-[-3a+2b-4b]+[-7a-a+b]-3b} (now you can collect like terms)<BR>\n" );
document.write( "=5a-{-[-3a-2b]+[-8a+b]-3b}<BR>\n" );
document.write( "=5a-{3a+2b-8a+b-3b} (now you can collect like terms again)<BR>\n" );
document.write( "=5a-(-5a)<BR>\n" );
document.write( "=5a+5a<BR>\n" );
document.write( "=10a<BR>\n" );
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document.write( "The mistake:<BR>\n" );
document.write( "=5a-{-[-3a+2b-4b]+[-7a-a+b]-3b} <BR>\n" );
document.write( "=5a-{3a-2b+4b-7a-a+b-3b} (when you remove a set of parentheses that follow a + sign, you leave all the signs that wewere inside the parentheses as they were before.<BR>\n" );
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document.write( "Also, collecting like terms when you have a chance makes the expression shorter and simpler. That reduces the risk of accidentally forgetting a term. Maybe you do not make that kind of mistakes, but I often do, so I prefer to somplify as often as I can. </SPAN>\n" );
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