Question

Complete the multiplication: 2EA

A. [14 −4]
B. [7 −4]
C. [14 4]
D. [7 −2]

Answer 1

`\left[\begin{array}{ccc}14&-4\end{array}\right]`

Explanation:

To find out the matrix 2EA we multiply EA first and then multiply it by 2

E=
`\left[\begin{array}{ccc}1&2\end{array}\right]`

A=
`\left[\begin{array}{ccc}3&0\\2&-1\end{array}\right]`

To get EA , multiply 1 and 2 with 3 and 2= 3+4=7

multiply 1 and 2 with 0 and -1= -2

EA=
`\left[\begin{array}{ccc}7&-2\end{array}\right]`

Now we multiply 2 with EA

So matrix becomes

2EA=
`\left[\begin{array}{ccc}14&-4\end{array}\right]`

Answer 2

In mathematics, a matrix (plural matrices) is a rectangular array of numbers, symbols, or expressions, arranged in rows and columns.

Given that

E = [ 1 2]

A = | 3 0|

| 2 -1 |

2EA = 2 [1 2] | 3 0|

| 2 -1 |

2EA = [ 14 -4]