document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230171>Question 230171</A>: <I><SPAN STYLE=\"word-break: break-all;\"> (4-7i)(4+7i) <BR>\n" );
document.write( "please solve and show work 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 #170476 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=170476\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (4-7i)(4+7i) <BR>\n" );
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document.write( "= 4*(4+7i) - 7i*(4+7i)<BR>\n" );
document.write( "= 16 + 28i - 28i - 49i^2<BR>\n" );
document.write( "= 16 - 49i^2<BR>\n" );
document.write( "i^2 = -1<BR>\n" );
document.write( "= 16 + 49<BR>\n" );
document.write( "= 65<BR>\n" );
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document.write( "These are similar to (a-b)*(a+b) = a^2 - b^2 EXCEPT the sign is plus.<BR>\n" );
document.write( "(a - bi)*(a + bi) = a^2 + b^2<BR>\n" );
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document.write( "Also, nothing is solved for, there's no variable in 65.  It's only simplified.\r<BR>\n" );
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