00:01
In this problem, we're being asked to solve the given nonlinear system of equations.
00:05
Well, to do that, i'm going to use the substitution method.
00:09
So i'm going to look at this first equation, x squared plus y squared is equal to 1.
00:14
And i'm just going to get x squared by itself.
00:16
To do that, i'm just going to subtract y squared from both sides of the equation.
00:22
So now we're going to have x squared is equal to 1 minus y squared.
00:27
So here's what i'm going to do.
00:28
I'm going to take 1 minus y squared and plug it.
00:31
It into x squared in that second equation because then i'll only have an equation with y's.
00:37
So let's see what we're have.
00:38
Well, we're going to have 1 minus y squared plus, well, i have that quantity of y plus 3 squared.
00:44
So i'm going to rewrite that as y plus 3 times y plus 3, and that's equal to 4.
00:50
So now what we have to do is we need to foil our binomials out.
00:55
So we're going to have 1 minus y squared plus, well, y times y is positive y squared, y times 3 is positive 3y, 3x, 3x, 3x, and 3 times 3 is positive 3y, and 3 times 3 is positive 9, and it's all equal to 4.
01:10
So now let's combine our like terms.
01:13
Well, i have negative y squared plus y squared, that's 0, they cancel.
01:18
I have 3y plus 3y, which is 6y, and then i have 1 plus 9, which is positive 10, and it's equal to 4...