00:01
Here we're given a system of equations that we want to solve.
00:03
The way we're going to solve it is by transforming these equations into a matrix and then performing a row operations on that matrix.
00:12
First, let's transform this system of equations into a matrix.
00:17
Since there are two variables, x and y, there are going to be two columns in the matrix.
00:22
And since there are two equations, there are going to be two rows.
00:26
So we take the coefficient of the first x here, put it here.
00:31
Then the coefficient of the y, there.
00:35
Same with here, the coefficient of x, coefficient of the y.
00:39
Do this line, which indicates that we're having two matrices basically, and then we put in the constants of five and three.
00:51
Now in order to solve this using row operations, we want to get into reduced echelon form.
00:58
Reduced row echelon form is when all the numbers on the diagonal are one.
01:03
Which they already are, and all the numbers below the diagonal are 0.
01:09
So we just have to get this equal to 0, then we'll have it in reduced row echelon form.
01:15
Now let's see, in order to row 2 into reduced row echelon form, we want to get this into a 0.
01:24
So we can do that by taking r2 minus r1.
01:30
This will cancel this out and we'll get a zero into this flat.
01:34
So we can do r2 minus r1 equals capital r2.
01:40
That just reminds us that when we're done with this equation, we plug this value back into r2.
01:46
Now you can do the subtraction.
01:49
R2 minus r1.
01:50
We get 1, 1, 3, minus 1, 2.
02:00
So now you can do the subtraction.
02:02
1 minus 1 is 0...