00:01
The concept in this problem is to solve a system of three linear equations with three variables.
00:09
The instructions in the problem say that you can use any method that you wish.
00:15
And you have studied several methods.
00:18
There's substitution.
00:23
There's elimination.
00:28
And there's the method of using matrices.
00:32
For this particular problem, i'm going to choose the elimination method.
00:38
It's just as a system that looks like it would be easily worked out with elimination.
00:44
So what i'm going to do in solving this problem, i'm going to take equations 1 and 2, and i'm going to eliminate the variable z.
00:56
Now, the reason i'm going to do that is because equation 3 does not have a z in it.
01:02
So we're going to take equation 1 and equation 2, and we're going to eliminate the c out of those equations.
01:24
So to do that, i need to turn this negative 2 into a positive, i'm sorry, a negative 4.
01:32
So i'm going to take that equation and multiply by 2...