Given [tex]\( A = \left[\begin{array}{cc} 2 & -1 \\ 5 & -2 \\ -3 & 4 \end{array}\right] \)[/tex] and [tex]\( B = \left[\begin{array}{cc} 6 & -1 \\ -6 & 5 \\ -1 & 0 \end{array}\right] \)[/tex],

what is [tex]\( A + B \)[/tex] ?

A. [tex]\(\left[\begin{array}{cc} -4 & -2 \\ -1 & -7 \\ -4 & 4 \end{array}\right]\)[/tex]

B. [tex]\(\left[\begin{array}{cc} -4 & 0 \\ 11 & -7 \\ -2 & 4 \end{array}\right]\)[/tex]

C. [tex]\(\left[\begin{array}{cc} 8 & -2 \\ -1 & 3 \\ -4 & 4 \end{array}\right]\)[/tex]

D. [tex]\(\left[\begin{array}{cc} 8 & 0 \\ -1 & 3 \\ -4 & 0 \end{array}\right]\)[/tex]



Answer :

To find the sum [tex]\( A + B \)[/tex] of two matrices [tex]\( A \)[/tex] and [tex]\( B \)[/tex], we add their corresponding elements. Given the matrices:

[tex]\[ A = \begin{pmatrix} 2 & -1 \\ 5 & -2 \\ -3 & 4 \end{pmatrix} \][/tex]

[tex]\[ B = \begin{pmatrix} 6 & -1 \\ -6 & 5 \\ -1 & 0 \end{pmatrix} \][/tex]

Let's add them element-wise.

1. For the element in the first row, first column:
[tex]\[ 2 + 6 = 8 \][/tex]

2. For the element in the first row, second column:
[tex]\[ -1 + (-1) = -2 \][/tex]

3. For the element in the second row, first column:
[tex]\[ 5 + (-6) = -1 \][/tex]

4. For the element in the second row, second column:
[tex]\[ -2 + 5 = 3 \][/tex]

5. For the element in the third row, first column:
[tex]\[ -3 + (-1) = -4 \][/tex]

6. For the element in the third row, second column:
[tex]\[ 4 + 0 = 4 \][/tex]

Putting all these together, we get the resulting matrix:

[tex]\[ A + B = \begin{pmatrix} 8 & -2 \\ -1 & 3 \\ -4 & 4 \end{pmatrix} \][/tex]

Comparing this with the given options:

- [tex]\(\begin{pmatrix}-4 & -2 \\ -1 & -7 \\ -4 & 4\end{pmatrix}\)[/tex]
- [tex]\(\begin{pmatrix}-4 & 0 \\ 11 & -7 \\ -2 & 4\end{pmatrix}\)[/tex]
- [tex]\(\begin{pmatrix}8 & -2 \\ -1 & 3 \\ -4 & 4\end{pmatrix}\)[/tex]
- [tex]\(\begin{pmatrix}8 & 0 \\ -1 & 3 \\ -4 & 0\end{pmatrix}\)[/tex]

The correct option is:

[tex]\[ \boxed{\begin{pmatrix}8 & -2 \\ -1 & 3 \\ -4 & 4\end{pmatrix}} \][/tex]