document.write( "Question 286846: write the first three terms of the expansion (a-b)^6 i am having difficulty with this. please help \n" ); document.write( "

Algebra.Com's Answer #208014 by Alan3354(69443) $\"\"$ $\"About$

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write the first three terms of the expansion (a-b)^6
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\n" ); document.write( "Use Pascal's triangle
\n" ); document.write( "1
\n" ); document.write( "1 1
\n" ); document.write( "1 2 1
\n" ); document.write( "1 3 3 1
\n" ); document.write( "1 4 6 4 1
\n" ); document.write( "1 5 10 10 5 1
\n" ); document.write( "1 6 15 20 15 6 1 6th power
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\n" ); document.write( "Notice that each element in the triangle is the sum of 2 above it, so you can fill it in quickly for \"small\" exponents. I wouldn't do it for an exponent of 50.
\n" ); document.write( "Since it's a-b, the signs alternate.
\n" ); document.write( "--> $\"a%5E6+-+6a%5E5b+%2B+15a%5E4b%5E2+-+20a%5E3b%5E3\"$
\n" ); document.write( "The exponents of a decrease while b's increase.\r
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