Let A be an n x n invertible matrix such that A^2 = 3A + I. Then, A^(-1) = ?
Let A be an n x n matrix such that det(A) = 4. If det(4(A^(-1))) = 64, then n = ?
Let A, B be two invertible matrices. Then the simplest form of B^2(2A^5B^2)^(-1)(2A^5) = ?
Please help me understand how to solve these 3 matrix questions.