00:01
4 number 40, we're given the equation x squared plus 6 bx equals 7b squared.
00:13
And we're sort of solitude the complete square method.
00:15
At first glance, it looks like a very peculiar, peculiar quadratic equation because of this second variable be.
00:24
But we're just going to treat the entirety of this.
00:28
So 6b is going to be essentially one.
00:32
Variable for our b over 2 and we have to actually complete the square on our binomial, which we can actually do right off the bat since our binomial is already in the correct form and isolate it on one side.
00:44
So we're looking for our b over 2 squared for add to both sides.
00:49
We're going to treat our 6b as the entire coefficient of x.
00:53
So it's going to be plugged in for our b.
00:58
And now we can simplify get 3b squared, which is going to be 9 b2.
01:04
Squared.
01:06
Now we'll add that to both sides.
01:07
From the left, we'll have x squared plus 6 bx plus our 9b squared equals 7b squared plus 9b squared.
01:28
So on the left, since this is, keep in mind this b squared here isn't actually, since it's not an x variable, this counts for pretty much a constant, even though we don't actually know what b is...