I was doing a few practice questions and was a bit confused about how the solution manual manipulated the I identity matrix. For example, Just say you had the following I - 2A = B where A and B are 2x2 matrices. B is given, but we need to find A. Therefore, shouldn't it be -2A = B - I A = -(1/2) * (B - I)? Because the book did it like this 2A = I - B A = (1/2) * (1 - B) Can anyone tell me why? Because both statements do not seem to be equivalent. (unless I'm missing something) Thanks in advance.