document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=409982>Question 409982</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In solving the equation (x + 1)(x – 2) = 54, Eric stated that the solution would be<BR>\n" );
document.write( "x + 1 = 54 => x = 53<BR>\n" );
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document.write( "(x – 2) = 54 => x = 56<BR>\n" );
document.write( "However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning.\r<BR>\n" );
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document.write( "I have tried this, when I substituted 53, and 56..I got 2862=54..I am way off..Please help..Thank you. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #288418 by </B><A HREF=/tutors/aboutme.mpl?userid=richard1234><B>richard1234(7193)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richard1234><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=richard1234><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=288418\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I don't know why I've seen so many problems with Eric struggling with a quadratic...\r<BR>\n" );
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document.write( "And no, it doesn't work because the 0-property rule only applies with 0. We cannot set each variable to 54 because the other variable can alter the value. The best way is to expand the left side and obtain\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2+-+x+-+2+=+54 ALIGN=MIDDLE  ALT=\"x%5E2+-+x+-+2+=+54\"   DISABLED_style= \"max-width:90%; height:auto;\" > --> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2+-+x+-+56+=+0 ALIGN=MIDDLE  ALT=\"x%5E2+-+x+-+56+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" >. Factoring, this becomes\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+-+8%29%28x+%2B+7%29+=+0 ALIGN=MIDDLE  ALT=\"%28x+-+8%29%28x+%2B+7%29+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" > --> now we can use the 0-property rule, x = 8 or x = -7 are the roots. </SPAN>\n" );
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