document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=644953>Question 644953</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In solving the equation (x + 3)(x + 1) = 48, Eric stated that the solution would be<BR>\n" );
document.write( "x + 3 = 48 => x = 45<BR>\n" );
document.write( "or<BR>\n" );
document.write( "(x + 1) = 48 => x = 47<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.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #405329 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=405329\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  In solving the equation (x + 3)(x + 1) = 48, Eric stated that the solution would be<BR>\n" );
document.write( "x + 3 = 48 => x = 45<BR>\n" );
document.write( "or<BR>\n" );
document.write( "(x + 1) = 48 => x = 47<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.<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Although the product of the 2 factos is 48, one of the factors does<BR>\n" );
document.write( "not have to be 48.  The factors could be 6 and 8, or 2 and 24, or<BR>\n" );
document.write( "any other combinations factors whose product is 48.<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "Solution:<BR>\n" );
document.write( "(x+3)(x+1) = 48<BR>\n" );
document.write( "x^2 + 4x + 3 = 48<BR>\n" );
document.write( "x^2 + 4x - 45 = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Factor<BR>\n" );
document.write( "x^2 + 9x-5x - 45 = 0<BR>\n" );
document.write( "Factor:<BR>\n" );
document.write( "x(x+9) -5(x+9) = 0<BR>\n" );
document.write( "(x+9)(x-5) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Since this product is zero, at least one of those factors<BR>\n" );
document.write( "MUST be zero.<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x+9 = 0 OR x-5 = 0<BR>\n" );
document.write( "x = -9 OR x = 5<BR>\n" );
document.write( "======================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );