document.write( "Question 156798: Please help me solve:
\n" ); document.write( "(x-y)^3-(x+y)^3
\n" ); document.write( "I belive this is the difference of perfect cubes, however, I'm not sure how to write it out!! \n" ); document.write( "
Algebra.Com's Answer #115602 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
Yes, you are correct.
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\n" ); document.write( "See:
\n" ); document.write( "http://www.purplemath.com/modules/specfact2.htm
\n" ); document.write( "for detailed information
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\n" ); document.write( "The special case is:
\n" ); document.write( "a^3 – b^3 = (a – b)(a^2 + ab + b^2)
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\n" ); document.write( "In your case:
\n" ); document.write( "(x-y)^3-(x+y)^3
\n" ); document.write( "'a' is (x-y)
\n" ); document.write( "'b' is (x+y)
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\n" ); document.write( "Therefore,
\n" ); document.write( "(x-y)^3-(x+y)^3
\n" ); document.write( "= ((x-y)-(x+y))((x-y)^2 + (x-y)(x+y) + (x+y)^2)
\n" ); document.write( "= (x-y-x-y)((x-y)^2 + (x-y)(x+y) + (x+y)^2)
\n" ); document.write( "= (-2y)((x-y)^2 + (x-y)(x+y) + (x+y)^2)
\n" ); document.write( "= (-2y)((x^2-2xy+y^2) + (x^2-y^2) + (x^2+2xy+y^2))
\n" ); document.write( "= (-2y)(x^2-2xy+y^2 + x^2-y^2 + x^2+2xy+y^2)
\n" ); document.write( "= (-2y)(x^2 + x^2 + x^2+y^2)
\n" ); document.write( "= (-2y)(3x^2 + y^2)\r
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