00:01
In this problem, we're being asked to solve the given quadratic equation by either completing the square or the quadratic formula.
00:07
And because our middle term is an even number and we have no coefficient in front of x squared, i'm going to actually solve this using the completing the square method.
00:15
So first, we have to move our constant term to the right -hand side of our equation.
00:19
So this will leave us with x squared minus 2x.
00:23
Then i'm going to leave a space, and this would be equal to 15.
00:27
So now, to complete the square, we have to find the value that, would make this perfect square.
00:32
To do this, we have a formula.
00:34
It's b divided by two squared.
00:36
And remember, b is the middle coefficient.
00:39
So we'd have negative two divided by two squared.
00:42
Well, negative two divided by two is negative one, and negative one squared is one.
00:47
So we'll have to add one.
00:48
But if we add one to the left -hand side, we have to add one to the right -hand side.
00:53
Well, now we can factor the left -hand side of our equation.
00:56
Remember, it will factor to one binomial that gets squared...