for (a+b)^n
term(r+1) = C(n,r)(a^(n-r) b^r)
so for (a-b)^9
term(5) = C(9,4)(a^5)(-b)^4
= 126a^5 b^4
Find the 5th term of the expression
1) (a-b) ^9
2 answers
31
1) (a-b) ^9
2 answers