00:01
Okay, this i want to expand with the pascal's triangle.
00:04
So the pascal's triangle, 1, 1, 1, 1, 1, 1 2, 1, 1, 3, 3, 1, and 1 4, and 1 4, and 1, and 1, and 4 1, is the one i need.
00:19
There's pascal's triangle, i'm just adding up 1 in 3, 3 and 3 and 1, 1 and 2, and so on.
00:31
Now, here then what we do, write down first 3 power 4, to put it in brackets.
00:41
Then write down 3, power 3 minus 2z power 1.
00:49
Then 3 squared minus 2 z squared.
00:56
There's a pattern here.
00:57
As you can see, powers of 3 are decreasing, powers of minus 2 z are increasing.
01:03
Here is 3, and the last one will be minus 2z power 4.
01:12
That's the first step.
01:14
Basically, this is a if you like, and all that is b.
01:19
So it's a power 4, a cubed, a squared, a1 and a0, that's gone.
01:26
And the b, b1, b2, b3, b power 4.
01:34
That's the pattern for the first step.
01:36
Then what you do is in front, pascal's triangle, 1, 4, 4, 1.
01:46
That's the answer, but of course you must make it simpler...