00:01
3z equals negative 3.
00:02
I'm going to go ahead and divide everything by 3 here to make it x minus 2y minus z equals negative 1.
00:08
On the next one, we have 2x plus 6z equals negative 22.
00:14
I'm going to divide everything by 2.
00:16
That's going to give me x plus 3z and negative 11.
00:21
Now i'm going to have 4x plus 7y plus 4z.
00:25
Well, they don't have anything in common, so i'm going to go ahead and just leave that as it is.
00:31
And we want to solve for x, y, and z.
00:33
Well, since i have a y that's not here, i'm going to go ahead and just use that.
00:37
So i'm going to multiply that first equation by 7, so it's going to be 7x minus 14y minus 7z equals negative 7.
00:46
And the second equation by 2, so it's going to be 8x plus 14y plus 8z equals to 6.
00:53
Adding these together, i'm going to have 15x plus z equals to negative 7x plus 14y plus 8z equals to negative 7.
00:58
And i'm going to go ahead and divide everything negative 1.
00:59
I can now combine that with this equation here.
01:02
So i'm going to do that.
01:04
I'm going to multiply this equation by negative 3.
01:07
So i'll have negative 3x.
01:09
I'm not.
01:10
I'm going to leave that one alone.
01:11
X plus 3z equals negative 11.
01:14
I'm going to multiply this one by negative 3.
01:17
That'll be negative 45x minus 3z is going to be positive 3.
01:23
So i'll have negative 44x equals negative 8.
01:28
Very ugly number.
01:29
So we have that'd be negative 44.
01:32
X is going to be 2 over 11.
01:35
So we have our x value, which i can use that ugly x value...