00:01
Okay, so i have a polynomial, a binomial specifically with two terms, a minus b to the third, and i'm multiplying it by itself total of eight times.
00:08
So when i'm multiplying the same binomial by itself a total number of times, i could use a shortcut to calculate and expand this polynomial using the binomial theorem, right? i can go from k equals zero to my exponent term, eight, eight choose k of my first term.
00:26
My first term is just a to the 8 minus k.
00:32
And then my second term, notice in my binomial theorem, i have to add the term.
00:36
So subtraction is the same thing as adding negative b to the kth term.
00:41
Okay.
00:42
I want to find the turn that has b to the ninth in it.
00:46
Okay, so how am i going to do that? well, in order to get b, i need to look at this term.
00:51
And i need to get negative b to the kth power to equal b to the ninth.
00:56
So how am i going to do that? well, note that this is, i'm multiplying a negative b...