00:01
Here we're given a function, we have 2x squared minus 11x minus 3 equals 0.
00:07
And we want to solve this by completing the square.
00:09
I want to start by saying i would not complete the square unless i'm forced to.
00:12
It is by far the hardest approach.
00:15
But having said that, you start off by factoring out of two out of the first two terms.
00:20
There are a few ways to do this, and everybody does it a little bit differently, but this is how i do it.
00:25
So i factor out of 2 meaning divide by 2 x.
00:28
And then i'm going to add some magic number we'll get two later.
00:33
I did not touch the three and then still equal to zero.
00:37
But wait, it's not because i need two.
00:40
If i add something in one side, i need to add it to the other side.
00:43
And really, i added two times that number.
00:45
So let's do two times and let's just replace that number.
00:48
Any number i put there, i have not changed anything.
00:51
Now, you're going to do negative b over two in this portion here...