 Hello and welcome to the session. Let us understand the following problem today. If A is equal to 1 1 minus 2 2 1 minus 3 5 4 minus 9 find the determinant of A. Now let us write the solution from the given problem. The determinant of A can be written as 1 1 minus 2 2 1 minus 3 5 4 minus 9. Now solving this we get 1 into 1 into minus 9 minus 4 into minus 3 minus 1 into 2 into minus 9 minus 5 into minus 3 minus 2 into 2 into 4 minus 5 into 1 which is equal to minus 9 plus 12 minus 1 into minus 18 plus 15 minus 2 into h minus 5 which is equal to 3 minus 1 into minus 3 minus 2 into 3 which is equal to 3 plus 3 minus 6 which is equal to 6 minus 6 which is equal to 0 therefore the required answer is 0. I hope you understood the problem bye and have a nice day.