Question

B= [2 8] A= [3 0]
6 3 2 -1
What is the BA

Answer 1

`BA=\begin{bmatrix}2 & 8 \\0.6 & 3\end{bmatrix}\cdot \begin{bmatrix}3 & 0 \\2 & -1\end{bmatrix}\\BA=\begin{bmatrix}2\cdot3+8\cdot2 & 2\cdot0+8\cdot(-1) \\0.6\cdot3+3\cdot2 & 0.6\cdot 0+3\cdot(-1)\end{bmatrix}\\BA=\begin{bmatrix}22 & -8 \\7.8 & -3\end{bmatrix}`

Answer 2

`\text{C.}\quad\left[\begin{array}{cc}22&-8\\7.8&-3\end{array}\right]`

Explanation:

It is convenient to let a spreadsheet or calculator do the tedious sum of products. Term C22 will be B21·A12 +B22·A22 = 0.6·0 +3·(-1) = -3, for example. Other terms are similarly computed. In general Crc will be the sum of Brx·Axc, where x = 1 or 2.