Mathematics
wallflower1201
2015-11-09 19:55:30
What is the coefficient of the term x^7y in the expression of (x+y)^8?
ANSWERS
maidawasim
2015-11-09 21:34:45

(r + 1)th term of (a + b)^n = nCr a^(n-r)b^r here n = 8 , r = 8-7 = 1,  a = a and b = y so we need second term  where r = 1:-   =  8 C 1 x^7y so the coefficient is 8

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