(a) Find A-1 and use it to solve the three systems Ax = b1, Ax = b2, and Ax = h3.
(b) Solve all three systems at the same time by row reducing the augmented matrix [A| b1 b2 b3] using Gauss-Jordan elimination
(c) Carefully count the total number of individual multiplications that you performed in (a) and in (b). You should discover that, even for this 2 × 2 example, one method uses fewer operations. For larger systems, the difference is even more pronounced, and this explains why computer systems do not use one of these methods to solve linear systems.
Let

And