
I'm sorry guys, but i found nothing in my preceding section about solving an equation for a matrix variable like this, i understand each of the symbols, but what am I even supposed to do here? can you cancel out the inverse by taking the inverse of both sides, subtracting I and then dividing by 2?
You are sort of on the right track. Your situation is as follows: \begin{align*} (I+2A)^{-1} & = B\\ I+2A & = B^{-1}\\ 2A & = B^{-1}-I\\ A& = \frac{1}{2}\left(B^{-1}-I\right). \end{align*}
So this problem is all about doing matrix algebra and finding inverse.