00:01
Find the number of solutions of the equations x2 minus x3 equal to 1 minus x1 plus 2 x3 equal to 2 and x1 minus 2x2 equal to 3.
00:17
We need to find how many solutions this system of equations have.
00:23
For that we can write this in the form a x equal to b.
00:29
Then a is equal to coefficient matrix 0 1 minus 1 minus 1 2 1 0 0 0 0 0 0 0 0 0 0 0.
00:46
Sorry 1 minus to 0 this is matrix a and x is matrix x 1 x2 x3 and b is the matrix of right side values 1 2 3 then a x equal to b clearly we have determinant a equal to 0 therefore we need to check for adjoined of a into b whether it's not equal to 0 equal to 0 so what.
01:31
Here, adjoined of a equal to when we find the matrix, adjoined of a is 422211 -211.
01:57
When we find the cofactors and taking the transpose, we get this matrix.
02:03
It's simple to find the add.
02:06
Joint using this matrix.
02:08
Okay, first a11 will be determinant of this.
02:16
Then the cofactor of this matrix will be a signed minus okay.
02:25
Deleting this row and this column determinant of this raised to minus 1 raise 2 i plus j...