"In the expansion of (2-ax)^5 the coefficient of x^2 is 5. Find the value of a".

I know I have to use the binomial theorem to help me, but I don't know how.

4 answers

I got it. :)
How did u get it?
According to the binomial theorem, the term with x^2 would be the third term. I plugged my known values into the "formula" for the third term, and made it equal to 5. Then I solved for a. Sorry, my explanation is kind of vague.
Cool, I appreciate you responding to my question.