If A = is is a matrix of order 2 × 2, such that |A| = –15, and represents the cofactor of , then find

If A and B are square matrices of order 3 such that |A| = –1, |B| = 3, then find the value of |2AB|.
If A is an invertible square matrix of order 3 and |A| = 5, then find the value of |adj A|.
If A = is is a matrix of order 2 × 2, such that |A| = –15, and represents the cofactor of , then find
Write the differential equation formed from the equation y = mx + c, where m and c are arbitrary constants.
If A = {1, 2, 3}, B = {4, 5, 6, 7} and f = {(1, 4), (2, 5),(3, 6)} is a function from A to B. State whether f is one-one or not.