00:01
I want to use row operations to get this matrix in reduce row echelon form.
00:08
Different ways to get there.
00:11
I'll offer you one path.
00:14
So let's first get a leading 1 in row 1.
00:18
We can do this by adding row 1 and 2 together, putting it in row 1.
00:31
So negative 2 plus negative 1 is, first 1.
00:40
So it's supposed to be a 2.
00:45
2 plus, just add them together, 2 minus 2 plus negative 1 is 1.
00:52
Negative 1 plus 0 is 0 plus 0 is 1.
00:56
1 plus negative 2 is negative 1.
00:59
And we'll keep rows 2 and 3 the same.
01:05
Now let's get 0 below the leading 1 in row 1.
01:11
And we can take rows 1 and 2, add them together, and put them in row 2.
01:16
So we get negative 1 plus 1 is 0, 0 plus negative 1 is negative 1, 1 plus negative 1 is 2, and negative 2 plus negative 1 is negative 2 minus 1, which is negative 3 in row 1 above, and 3 are the same.
01:52
Now let's get a 0 in row 3 column 1 by adding row 3 to 2 times row 1 above and putting that in row 3.
02:06
So it would be negative 2 plus 2 times 1, which is 0, 1 plus 2 times negative 1 is negative 1.
02:20
0 plus 2 times 1 is 2...