00:01
Okay, in this problem we have the binomial, a plus b squared, raised to the power 12, and we're asked for the term, which is b8 in this expansion.
00:13
Okay, so let's think about how we get a b to the power 8.
00:16
Okay, we've already got a b squared.
00:18
So we know that we don't have to raise this to the power 4 in order to get it to equal b to the power 8.
00:25
Okay, what does that mean? that means our a must have been raised to a power that when added with 4, equals 12.
00:33
So something plus 4 equals 12.
00:35
Hopefully everyone can kind of tell that's 8.
00:38
So this must be 8 of the power 8.
00:41
And then we'd have our binomial coefficient in here as well.
00:43
Don't forget about that.
00:45
Okay.
00:45
That will be 12 choose something.
00:47
Or is that something? it's always the exponent on the last term.
00:52
So four here.
00:53
Oh, sorry about that...