### Home > PC > Chapter 12 > Lesson 12.1.1 > Problem 12-9

12-9.

Using the lower left entry from part (a) and matrix *I*:

−1(*a*) + 2(*c*) = 0

Now repeat this process for the rest of the entries.

Look at part (b) and remember that *M*(*M*^{−1}) = *I*.

12-9.

Using the lower left entry from part (a) and matrix *I*:

−1(*a*) + 2(*c*) = 0

Now repeat this process for the rest of the entries.

Look at part (b) and remember that *M*(*M*^{−1}) = *I*.