00:01
In this question, we want solution of this system.
00:05
That means we want value of x, y and z.
00:09
Here, we can write this as matrix a multiplied by matrix x equal to matrix b.
00:21
Here, matrix a is matrix of coefficients of x, y and z.
00:28
That means in first row we can write 1, 1 and 1, coefficients of x, y, z.
00:37
And in second row 1, 1 and minus 4, 1, 1 minus 4, and in 3rd row, minus 4, 1 1, 1, 1.
00:46
1, minus 4, 1, 1.
00:51
This is matrix a.
00:54
Now, matrix x is column matrix of elli, demands x y z x y z and matrix b is column matrix of 510 0 510 0 now to find out x this a will come this side and x will be a inverse b now to find out x we have to find out x we have to solve for a inverse.
01:35
Now we know that a inverse equal to 1 divided by determinant a multiplied by adjoint a.
01:45
Now here we find out we will find out determinant a.
01:53
Here we can see that determinant a will be we solve with respect to first row.
02:00
Now with respect to this one we can 1 minus 4 that means 1 plus 4 now with respect to this 1 minus 1 we get 1 minus 4 that means minus 16 1 minus 16 now with respect to this 1 minus 4 that means plus 4 1 plus 4 now we get 1 plus 4 4 that means 5 multiplied by 1 that means 5 1 minus 16 minus 15 multiplied by minus 1 that means plus 15 now 1 plus 4 5 5 multiplied by 1 will be 5 we get 25 this is determinant a now adjoint of matrix a will be we can write here adjoint of the matrix a will be transpose of co -factors of elements of matrix a that means co -factor of 1 will be 1 minus minus 4 that means 1 plus 4 that means 5 now co -factor of this 1 will be 1 minus 16 that means minus 15 but here we have to multiply it with minus therefore we get plus 15.
03:41
Now, co -factor of this one will be 1 plus 4, that means 5.
03:48
Now, co -factor of this one will be 1 minus 1, that means 0.
03:54
Now, co -factor of this one will be 1 plus 4, that means 5.
04:02
Now co -factor of this minus 4 will be 1 plus 4 that means 5 but here we have to multiply with minus now co -factor of this minus 4 will be minus 4 minus 1 that means minus 5 now co -factor of this 1 will be minus 4 minus 1 that means minus 5 but here we have to multiply with minus therefore we get plus 5...