0:00
Okay, let's look at this problem.
00:01
First, we want to simplify this system of equations.
00:06
So i1 minus i2 minus i3 is 0.
00:12
For the second equation, we have minus 6i1 minus 3 i3 equals to minus 24.
00:29
And for the third one, we have minus 6i minus 6i minus 6 i1 minus 6 i 2.
00:36
Equals to minus 3 minus 36 okay for the second equation actually we can turn this uh we can divide it by negative 3 okay so we have here is here is 2 and here is 1 so i just write a plus so the right side is we divided by negative 3, so it remains is 8.
01:20
It is 8.
01:27
Okay, so now for the third equation, okay, how do we deal with this? we can simplify by, divided by minus 6 to the both side.
01:41
So here i have 1 and the plus plus i2, and the right side is 6.
01:54
6.
02:05
Okay, so now let's turn this into a matrix.
02:11
So the first column is i1, so i have 1, i 1, 2, i 1 and 1, so i have 1 2, i 1.
02:24
So i have 1 2, i 2, so i have negative 1, 0, and 1.
02:31
For the 3rd column, i have minus 1, 1 and 0.
02:37
And here is 086.
03:17
Okay, let's label this is row 1, this is row 2, and this is row 3.
03:22
The first step i want to do it, so i want to add row 1 plus row 3 and assign this to 0 0 .3.
03:32
So i have 1, negative, negative 1, and 2 .01, i have 2 0 .991.
03:44
This is 0, this is 8, this is 6.
03:57
So now what i want to do is this is row 1, this is row 2, and this is row 3.
04:08
So what i want to do is i want to add row 2 to row 3.
04:14
So here i have 1 -191.
04:26
Okay, so here i forget to say i want to assign this to row 3.
04:30
So here i have 2 .01.
05:00
Oh, so here should be 14...