document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=223968>Question 223968</A>: <I><SPAN STYLE=\"word-break: break-all;\"> My son's homework question is:\r<BR>\n" );
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document.write( "Find the value(s) of a for which the equation is an identity.\r<BR>\n" );
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document.write( "a(2x+3) = 9x + 12 - x\r<BR>\n" );
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document.write( "What exactly are they asking him to do here?  I don't understand what they are looking for.  Should he solve for a, or for x in terms of a?\r<BR>\n" );
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document.write( "thanks,<BR>\n" );
document.write( "Andrea </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #167354 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=167354\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Find the value(s) of a for which the equation is an identity.\r<BR>\n" );
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document.write( "a(2x+3) = 9x + 12 - x<BR>\n" );
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document.write( "The problem wants to know the value of 'a'.<BR>\n" );
document.write( "Start by distributing the 'a' to the terms inside the parenthesis:<BR>\n" );
document.write( "2ax+3a = 9x + 12 - x<BR>\n" );
document.write( "Combine like-terms on the right:<BR>\n" );
document.write( "2ax+3a = 8x + 12<BR>\n" );
document.write( "Looking at the 'x' terms:<BR>\n" );
document.write( "(2a)x+3a = (8)x + 12<BR>\n" );
document.write( "To get the SAME number of x's on the left as the right, the following MUST be true:<BR>\n" );
document.write( "2a = 8<BR>\n" );
document.write( "a = 4<BR>\n" );
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document.write( "Similarly:<BR>\n" );
document.write( "3a = 12<BR>\n" );
document.write( "a = 4<BR>\n" );
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document.write( "Therefore, a=4\r<BR>\n" );
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document.write( " </SPAN>\n" );
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