Science

Math

Humanities

... and beyond

Socratic Meta
Featured Answers

Topics

Question #10746

1 Answer

A. S. Adikesavan

Dec 25, 2016

#-1024#

Explanation:

#(1+2x-x^2)^4#

#=(2-(1-x)^2)^4#

= terms that do not contribute to the coefficient of #x^7

the last term ((2-x)^2)^4#, using binomial expansion

So, the coefficient of #x^7#

= the coefficient in the expansion of #((2-x)^2)^4)=(2-x)^8#

#=-8C_7 2^7=8 X 128=1024#, using binomial expansion

Related questions

See all questions in Pascal's Triangle and Binomial Expansion

Impact of this question

6258 views around the world

You can reuse this answer
Creative Commons License