Sample Quiz 7 Questions
  * What is $A^{-1}$ if $$A = \begin{bmatrix} 1 & 0 & 1 \cr 0 & 1 & 1 \cr 0 & 0 & 1 \end{bmatrix}$$
  * Write $$B = \begin{bmatrix} 1 & 2 & 3 \cr 4 & 5 & 6 \cr 7 & 8 & 9 \end{bmatrix}$$ in row-echelon form.
  * What are the image and kernel of the matrix $$C = \begin{bmatrix} 1 & 1 & 1 \cr 1 & 2 & 1 \cr 2 & 3 & 2 \end{bmatrix},$$
find a basis for the image and kernel of $C$.