00:01
In this question, we are asked to solve the given system of linear equations.
00:04
First, we need to construct the augmented matrix of the system of equations.
00:09
The augmented matrix is simply a matrix which consists of the coefficients in front of x1, x2 and x3, and the right -hand sides.
00:17
So the first row is going to be 2, negative 5, 5, negative 33, which corresponds to the first equation.
00:25
The second equation corresponds to 2, 0, 3 and negative 16.
00:30
The last equation corresponds to 7, 0, 9 and negative 47.
00:43
Now we will divide the first row by 2.
00:49
And after doing that, after dividing the first row by 2, 2 becomes 1, negative 5 becomes negative 5 halves, and 5 becomes 5 halves, and negative 33 halves.
01:22
The next step is to multiply the first row by negative 2 and added, to the second row and multiply the first row by negative 7 and add it to the last row.
01:41
So what we are going to get in the second row, we will rewrite the first row.
01:45
1, negative 5 halves, 5 halves and negative 33 halves.
01:57
In the second row we are going to get 1 times negative 2 is negative 2 plus 2 is 0.
02:06
Negative 5 halves times negative 2 equals to 5, 5 plus 0 is 5.
02:12
5 .5 times negative 2 is negative 5.
02:16
Negative 5 plus 3 is negative 2.
02:20
And negative 33 1 .3 minus 16 equals to 17.
02:30
Now in the third row we are going to get 1 times negative 7 plus 7 is going to be 0.
02:39
Negative 5 1 times negative 7 equals to 35 halves.
02:45
35 halves plus 0 is 35 halves.
02:46
5 halves plus 0 is 35 halves.
02:52
5 halves times negative 7 is negative 35 halves plus 9 is going to be, now let's do some calculation, negative 35 halves, plus 9 is negative 35 halves, plus 18 halves equals to negative 17 halves...