binomial question from 2004 hsc (1 Viewer)

[Benmc]

can someone please explain to me question 7b. from last years 3 unit paper.
i don't get where k thing???

 

[serge]

relax, you've got a whole year to figure it out

do you understand what nCk is about?

EDIT- I guess if you got up to Q7 in the HSC paper you must know alot

 

[Dumsum]

I actually just went through this question myself. There's a lottalottalotta working, which parts specifically? What do you mean by the "k thing?"

 

[justchillin]

The "k" thing...what? They're just equating coefficiants of x^k, where k is any positive integer...

 

[Stefano]

I do 4u math and am sitting the 3u exam tomorrow and I don't understand all of 7b either.

 

[rama_v]

Heres the solution

I typed it up a couple of weeks ago, found it lying around

 

[Stefano]

Thanks!

However, what troubles me with these questions is not the tedious mathematics but, rather, a lack of approach.

 

[rama_v]

Very true
Most people (including me) would never be able to get those in exam conditions.

 

[Benmc]

relax, you've got a whole year to figure it out

do you understand what nCk is about?

EDIT- I guess if you got up to Q7 in the HSC paper you must know alot

nah i'm on my bro's comp thats why its in his name.
wat i dont get is how they equate the k thing. it just appeared out of nowhere