document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=491531>Question 491531</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Really need help on this please:\r<BR>\n" );
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document.write( "Megan factored the expression 28x^2+x-15 as (4x-3)(7x+5). But when Jacob applied the FOIL principle and multiplied out (4x-3)(7x+5), he got 28x^2-x-15; thus, Megan’s solution does not appear to check. Why is that? Please help Megan to understand this better. Explain your reasoning and correctly factor the original expression, if possible. If the expression is prime, so state. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #334660 by </B><A HREF=/tutors/aboutme.mpl?userid=oberobic><B>oberobic(2304)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oberobic><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=334660\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 28x^2 +x -15<BR>\n" );
document.write( "(4x -3)(7x + 5)<BR>\n" );
document.write( "FOIL<BR>\n" );
document.write( "28x +20x -21x -15<BR>\n" );
document.write( "28x -x -15<BR>\n" );
document.write( ".<BR>\n" );
document.write( "(4x +3)(7x -5)<BR>\n" );
document.write( "FOIL<BR>\n" );
document.write( "28x -20x +21x - 15<BR>\n" );
document.write( " 28x +x -15<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Done </SPAN>\n" );
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