00:01
We want to solve the equation x squared plus 7 x minus 8 equals 0 by completing the square.
00:05
To do this, let's add 8 to both sides.
00:08
That way we can complete the square on the left side by coming up with a constant that allows us to write this as a perfect square.
00:17
And then we can apply the square property.
00:20
So how do we complete the square here? we take the coefficient on the x term 7, take half of it, seven halves, and then square it.
00:29
7 .5 squared is 49 fourths.
00:32
That's what we're going to add to both sides.
00:35
So we can write it as a perfect square trinomial, x plus 7 .5 squared.
00:40
And to add these together on the right hand side of the equation, let's think of 8 in terms of 4ths...