00:01
All right, so for the question today, we are asked, we need to use the binomial theorem to find the indicated coefficient or term.
00:08
And what we need to find today is the third term.
00:12
So the third term of the following formula, and that is 3x minus 2 to the power of 9.
00:23
So we do this by using the binomial theorem to find this required term.
00:28
The binomial theorem for this question looks as followed.
00:32
So it's going to be 9, 7, and then 3x to the power of 7, and then negative to the power of 9 minus 7.
00:59
9 minus 7.
01:01
And we know that we can turn this 9 and 7 as 9 being our n and 7, and 7 being our k, using the formula we know that can evaluate binomial expressions, and that is n factorial over k factorial times n minus k factorial.
01:26
So we're going to use that on our next line here.
01:29
And that is going to be 9 factorial over 7 factorial, and then 9 minus 7 is 2 factorial...