### Home > PC3 > Chapter 11 > Lesson 11.1.3 > Problem11-46

11-46.

Complete the following matrix computations.

1. $\left[ \begin{array} { l l } { 1 } & { 2 } \end{array} \right] \left[ \begin{array} { c c } { 2 } & { - 1 } \\ { 4 } & { 0 } \end{array} \right]$

$\begin{bmatrix}1(2)+2(4)\\1(-1)+2(0)\end{bmatrix}$

2. $\left[ \begin{array} { l l } { 2 } & { 4 } \end{array} \right] \left[ \begin{array} { c c } { 2 } & { - 1 } \\ { 4 } & { 0 } \end{array} \right]$

3. Use the results of the pattern of parts (a) and (b) to state the product $\left[ \begin{array} { c c } { 10 } & { 20 } \end{array} \right] \left[ \begin{array} { c c } { 2 } & { - 1 } \\ { 4 } & { 0 } \end{array} \right]$ without computing.

If part (a) is $^\prime AB^\prime$, then part (b) is $'(2A)B'$. What is part (c)?

4. Verify your result for part (c) by multiplication.