00:01
All right, we want to solve for x.
00:02
So to make this easier, we're going to move one of the square roots to the right.
00:07
So i'm going to subtract square to 1 minus x.
00:14
So we have here is square root of 1 plus x equals 2 minus square root of 1 minus x.
00:22
Then to get rid of the square root on the left, we're going to square both sides.
00:30
Make sure you put a parentheses on the right -hand side because i have two terms there.
00:33
On the left, when we square root, we're left with what's underneath the radical.
00:37
So we get 1 plus x.
00:40
On the right, you're going to have a binomial, and we have to foil that binomial.
00:53
So 2 times 2 is 4.
00:55
Outer gives me a negative 2 square to 1 minus x.
00:59
Enter negative 2 square to 1 minus x.
01:03
And your last will give us a positive square to 1 minus x squared.
01:10
Combine like terms on the right.
01:16
Not doing anything with the left yet.
01:17
We have 4 minus 4 square to 1 minus x's.
01:22
These two in the middle are the same.
01:25
Just add the numbers in front.
01:27
And then when i square the square root, again, i'm left with what's underneath plus 1 minus x.
01:33
I'm going to combine like terms on the right.
01:35
I have a 4 and a 1 becomes a 5 minus 4 square to 1 minus x minus x.
01:44
Now i still have a square root.
01:46
So in order to get rid of it, i have to move everything that's not a square root to the left.
01:49
So i'm going to start by subtracting 5 and adding x...