Thread: Expanding and subtracting binomials

I'm working on expanding binomials and I currently understand how to expand basic ones using the binomial theorem. But due to transferring to my Precalc class late, I missed the lecture on them. Could someone explain how to expand and simplify this expression using the binomial theorem?



Thanks in advance!

Originally Posted by zsf1990

I'm working on expanding binomials and I currently understand how to expand basic ones using the binomial theorem. But due to transferring to my Precalc class late, I missed the lecture on them. Could someone explain how to expand and simplify this expression using the binomial theorem?



Thanks in advance!

OH, Come on!

I don't think I understand what you mean. The book gives as the solution. I got by applying the 2 and 5 after expanding, then combining like terms. I'm not sure where I messed up.

Originally Posted by zsf1990

I don't think I understand what you mean. The book gives as the solution. I got by applying the 2 and 5 after expanding, then combining like terms. I'm not sure where I messed up.

May I ask you, if you know the answer then why are you asking?

Knowing the answer does me no good if I don't know how to get there. I know how to expand the binomial and how to subtract the two expanded terms. What I don't understand is what to do with the 2 and the 5.

Originally Posted by zsf1990

Knowing the answer does me no good if I don't know how to get there. I know how to expand the binomial and how to subtract the two expanded terms. What I don't understand is what to do with the 2 and the 5.

Once you expand each of the terms using the Binomial Theorem, multiply each term through by 2 or 5 (depending on which number is out the front).

However, Plato's advice gives you an easier alternative form to work with.