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bobbym
2013-06-30 01:04:27

No bother, happens to me all the time.

romani
2013-06-30 01:02:33

Oh, of course! I was making a really stupid mistake.
Sorry for bothering you with such a silly question!
Thank you very much for helping me! c:

bobbym
2013-06-29 04:21:04

Hi;

Welcome to the forum.

The expansion of that is

from which you see 10a^3  is the constant term.

10 a^3 = - 270

a^3 = - 27

a = -3

Or:

Your latexing did not come out.

That is derived from the binomial theorem. You only have to solve the equation.

bob bundy
2013-06-29 04:05:39

hi romani

Welcome to the forum.

This involves the binomial theorem.  Do you know this?

Bob

romani
2013-06-29 03:51:45

hello! so, I've came accross a problem I can't solve at all :c. The problem is as it follows:

The constant term of

is equal -270, then a=?

I searched how to solve it and found only one solution, but I didn't understand what was done... they turned
into
and somehow found that k = 2. also, they found "
", which give us a = -3.

That's actually the right answer, but I can't figure out what was done to solve this problem... :c Can you guys explain it to me?

Thanks c: