Sorry for bothering you with such a silly question!

Thank you very much for helping me! c:]]>

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.

]]>Welcome to the forum.

This involves the binomial theorem. Do you know this?

Bob

]]>**The constant term of **

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:

]]>