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 #167359 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><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=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=167359\">put this solution on YOUR website!</A><BR><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" );
document.write( "\n" );
document.write( "a(2x+3) = 9x + 12 - x\r<BR>\n" );
document.write( "\n" );
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" );
document.write( "\n" );
document.write( "thanks,<BR>\n" );
document.write( "Andrea\r<BR>\n" );
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document.write( "a(2x + 3) = 9x + 12 - x\r<BR>\n" );
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document.write( "a(2x + 3) = 9x - x + 12\r<BR>\n" );
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document.write( "a(2x + 3) = 8x + 12\r<BR>\n" );
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document.write( "a(2x + 3) = 4(2x + 3)\r<BR>\n" );
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document.write( "As seen, there is a common factor on each side of equation, and that common factor is 2x + 3\r<BR>\n" );
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document.write( "As can be seen also, \"a\" MUST equal 4. \r<BR>\n" );
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document.write( "If this is still unclear, let's consider the following:\r<BR>\n" );
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document.write( "b(2 + 1) = 5(2 + 1). We're supposed to get \"b\" = 5.\r<BR>\n" );
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document.write( "Let's go the long way.\r<BR>\n" );
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document.write( "b(2 + 1) = 5(2 + 1)\r<BR>\n" );
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document.write( "2b + b = 5(3)\r<BR>\n" );
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document.write( "3b = 15\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b+=+15%2F3+=+5 ALIGN=MIDDLE  ALT=\"b+=+15%2F3+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Therefore, as stated previously, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28a+=+4%29 ALIGN=MIDDLE  ALT=\"highlight_green%28a+=+4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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