00:01
We're being asked to use the completing the square method to solve this equation.
00:04
Well, to do that, we first must move the constant term to the other side of the equation.
00:09
In other words, we have to subtract 18 from both sides.
00:14
So now we're going to be left with y squared plus 8y equals negative 18.
00:23
Now we have to figure out what can be added to the left -hand side to make it a perfect trinomial.
00:29
Well, to do this, we simply take half of the coefficient of the y term and square.
00:33
Well, the coefficient of our y term is 8.
00:37
So what we're going to do is we're going to take 8 divided by 2 and square it.
00:42
Well, 8 divided by 2 is 4, and 4 squared is 16.
00:46
So what we're going to be left with is y squared plus 8y plus 16.
00:53
But if i add 16 to one side of the equation, i must also add 8.
00:59
Excuse me, if i add 16 to one side of the equation, i must also add 16 to the other side.
01:04
Side of the equation in order to keep it balanced.
01:07
Well, we can now factor the left -hand side of the equation.
01:10
And remember, it's a perfect square, trinomial...