00:01
So we're being asked to solve the given nonlinear system of equations.
00:05
Now, what i'm going to do is i'm going to use the substitution method to do this.
00:11
Now, i am going to use the second equation.
00:14
However, i'm not going to substitute that expression in for x because then i'm going to end up having the square rate and i'm going to get y to the fourth terms and that could get a little confusing.
00:22
So what i am going to do is i'm going to get y squared by itself by adding five to both sides of the equation.
00:29
So now what i have is that x plus 5 is equal to y squared.
00:36
So now what i can do is i can substitute x plus 5 in place of y squared in the first equation.
00:42
So what we're going to have is x squared plus x plus 5 is equal to 25.
00:49
Well, now we have a quadratic equation.
00:52
So i have to get it set equal to zero.
00:54
So to do that, i'm going to subtract 25 from both sides.
00:57
And now we're left with x squared plus x minus 20 equals zero so now i can solve this equation by factoring well what factors of negative 20 will add to positive 1 well that would be negative 5 and positive 4 so my two factors are x plus 5 and x minus 4 so now to solve i simply set both of the equations equal to 0 so we have x plus 5 equals 0 and x minus 4 equals 0 and now we solve well for the first equation, we must subtract 5 from both sides, so x could be negative 5, and from the second equation, we're going to add 4 to both sides, so x could equal to 4.
01:41
So now that we've found our values for x, we have to find their corresponding y values.
01:47
But remember, in that second equation, we already got y squared by itself.
01:51
So what i'm going to do is go to a different page, and remember, we had the equation x plus 5 is equal to y squared.
01:59
And looking back, remember, we just found we had for x values negative 5 and 4.
02:06
So first, i'm going to take negative 5 and substitute it in for x.
02:11
I'm also going to put over here, so i don't forget, our other solution is x is 4.
02:15
So when i substitute negative 5 in for x, we're going to have negative 5 plus 5 equals y squared.
02:23
Well, negative 5 plus 5 is 0...