Question

14. Which term in the expansion of (92-2/9)18 will have 912?

Answer 1

We have to use Binomial Expansion which I have forgot now..
Can anybody know about Binomial Expansion...???

Answer 2

r+1 th term = nCr a ^(n-r) b^r

thats for ( a + b)^n

Answer 3

so (r+1)th term = 18Cr 92^(18-r)(- (2/9)^18)

Answer 4

@cwrw238 , there it will come r in place of 18 in power of b???

Answer 5

yes the last part is (-2/9)^r not (-2/9)^18

Answer 6

\[(r+1)^{th}=^nC_r.a^{n−r}.b^r\]

Here n= 18, a = 92 and b = 2/9

\[912=^{18}C_r.(92)^{18−r}.(\frac{−2}{9})^r\]

Answer 7

yes thats correct

Answer 8

I think somewhat that the question is wrong...

Answer 9

yes i agree