document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=108141>Question 108141</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I can't seem to figure this one out can you help me please?<BR>\n" );
document.write( "4n^2 + 20n=0  I have to solve the equation. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #78789 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><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=78789\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You can solve this by first noting that both of the terms on the left side contain the unknown<BR>\n" );
document.write( "variable n.  Therefore, n can be factored out to give:<BR>\n" );
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document.write( "n*(4n + 20) = 0<BR>\n" );
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document.write( "Then notice that the left side of this equation will be zero (and therefore equal to the right<BR>\n" );
document.write( "side) if either of the two factors on the left side is zero ... because multiplication<BR>\n" );
document.write( "by zero results in the product being zero.<BR>\n" );
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document.write( "So, this equation will be true if either n = 0 or if 4n + 20 = 0<BR>\n" );
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document.write( "You can immediately tell that n = 0 is one solution to the problem. Next you need to solve<BR>\n" );
document.write( "the equation 4n + 20 = 0 to find the other value of n that will make the equation true.<BR>\n" );
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document.write( "4n + 20 = 0 <==== subtract 20 from both sides to get rid of the + 20 on the left side<BR>\n" );
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document.write( "4n = -20 <=== solve for n by dividing both sides by + 4 to reduce the equation:<BR>\n" );
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document.write( "n = -20/4 = -5<BR>\n" );
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document.write( "In summary, if n = 0 or if n = -5 the equation of the original problem will be true, so<BR>\n" );
document.write( "those are the two answers for n.<BR>\n" );
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document.write( "You can check these answers by going back to the original problem and substituting them<BR>\n" );
document.write( "(one at a time) to make sure the equation is true for that value.<BR>\n" );
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document.write( "So start with:<BR>\n" );
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document.write( "4n^2 + 20n = 0 <BR>\n" );
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document.write( "Let n = 0 and the equation becomes:<BR>\n" );
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document.write( "4(0)^2 + 20*0 = 0<BR>\n" );
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document.write( "This is true because both terms on the left side contain 0 as a multiplier.<BR>\n" );
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document.write( "Next let n = -5. When you do the equation becomes:<BR>\n" );
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document.write( "4*(-5)^2 + 20(-5) = 0<BR>\n" );
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document.write( "Squaring the -5 results in +25, making the equation become:<BR>\n" );
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document.write( "4*25 + 20*(-5) = 0<BR>\n" );
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document.write( "4*25 is 100 and 20*(-5) is -100 so the equation is equivalent to:<BR>\n" );
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document.write( "100 - 100 = 0<BR>\n" );
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document.write( "This also is true. So our two answers for n work ... n = 0 and n = -5<BR>\n" );
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document.write( "Hope this helps you to understand the problem and how to get the solution.<BR>\n" );
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document.write( " </SPAN>\n" );
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