−5

3
2

⋅(−1
2
1

)

1 answer

It appears that you're trying to perform a matrix multiplication with two matrices. However, the way the matrices are presented is a little unclear due to the formatting.

Assuming you mean the following matrices:

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

and

\[ B = \begin{pmatrix} -1 & 2 \ 1 & 1 \end{pmatrix} \]

To multiply these two matrices \( A \) and \( B \), you can use the matrix multiplication formula. The element \( (i,j) \) in the resulting matrix \( C = A \cdot B \) is calculated as follows:

\[ C_{ij} = \sum_{k} A_{ik} B_{kj} \]

Calculating the elements of \( C \):

  1. For \( C_{11} \): \[ C_{11} = (-5)(-1) + (3)(1) = 5 + 3 = 8 \]

  2. For \( C_{12} \): \[ C_{12} = (-5)(2) + (3)(1) = -10 + 3 = -7 \]

  3. For \( C_{21} \): \[ C_{21} = (2)(-1) + (1)(1) = -2 + 1 = -1 \]

  4. For \( C_{22} \): \[ C_{22} = (2)(2) + (1)(1) = 4 + 1 = 5 \]

Thus, the resulting matrix \( C \) is:

\[ C = \begin{pmatrix} 8 & -7 \ -1 & 5 \end{pmatrix} \]

If my assumption about the matrices is incorrect or if you're looking for something else, please clarify!