00:01
Hello, here we're giving the quadratic x squared minus 4x minus 7 is equal to 0.
00:05
We want to solve this by completing the square.
00:07
So how we can complete the square is, i mean, the way i do it is i want first the constant term by itself.
00:13
So we can just move the 7 to the right side of the equation.
00:15
So we get x squared minus 4x is then equal to 7.
00:20
It becomes positive.
00:21
We add to the right.
00:22
And now complete the square, we just write down the left side to be right x squared minus 4x.
00:27
Now, if we get the square, we have to have the coefficient on the leading coefficient has to be one, which it is.
00:34
So we just now just take half of the coefficient on a linear term.
00:38
So half of negative four is negative two.
00:41
Then we square that.
00:42
So negative two squared is positive four.
00:45
So we're going to add four to the right.
00:48
But then we have to make this to be equal, we better add four to the right as well.
00:53
We'll add four to the right as well.
00:55
But now the left side is going to factor...