document.write( "Question 90921This question is from textbook Elementary Algebra
\n" ); document.write( ": Hello,
\n" ); document.write( "I cannot find topic - Factoring a Perfect-Square Trinomial
\n" ); document.write( "My problem is:
\n" ); document.write( " 16x^2 - 40x + 25 - Okay I know that the first & third #'s need to squared.\r
\n" ); document.write( "\n" ); document.write( " But I'm getting lost trying to break it down.....the examples gives:\r
\n" ); document.write( "\n" ); document.write( " (4x)^2 - 2(4x)(5)+ 5^2 = (4x-5)^2\r
\n" ); document.write( "\n" ); document.write( "I just can't seem to figure out how they got there.
\n" ); document.write( "Thanks for any help you can give...hope it makes sense...
\n" ); document.write( "Cristina
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #65979 by scott8148(6628) $\"\"$ $\"About$

You can put this solution on YOUR website!
you can build a perfect square trinomial from scratch ... (m+n)^2 ... FOILing gives m^2+mn+mn+n^2 or m^2+2mn+n^2\r
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\n" ); document.write( "\n" ); document.write( "in your problem, m is 4x and n is -5 ... (4x-5)^2=(4x)^2+4x(-5)+4x(-5)+(-5)^2=16x^2-20x-20x+25=16x^2-40x+25\r
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\n" ); document.write( "\n" ); document.write( "the example doesn't have the minus sign associated with the 5, which could be causing confusion \n" ); document.write( "

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