Question

What is the third term of (a + b)^11?

Answer 1

if you know about binomial expansion using combination notation it is

\[^{n}C_{r} a^{n - r}b^{r}\]

in your question n = 11 r = 2

Answer 2

can you explain idk what is binomial expansion

Answer 3

Some good notes would help.

Answer 4

ok... do you know about pascals triangle...?

Answer 5

Like this one,
http://www.sparknotes.com/math/algebra2/binomialexpansion/section2.rhtml

Answer 6

well that makes it easy... go and read the notes... its impossible to do a problem if you don't have an understanding of the key concepts...

Answer 7

yea i do

Answer 8

is this correct ? C(11,2) a^9 b^2

Answer 9

it is correct... you just need to evaluate the combination

\[^{11}C_{2} = \frac{n!}{r!(n - r)!}= \frac{11!}{2!(11 - 2)!}\]

Answer 10

so i need to solve 11!/2!(11 - 2)!? right