What is the result of multiplying the matrix \( A = \begin{bmatrix} 5 & 6 \\ 7 & 8 \end{bmatrix} \) by the scalar \( k = 4 \)?

Step 1 ：To multiply a matrix by a scalar, we simply multiply each element of the matrix by the scalar. In this case, we multiply each element of matrix \( A \) by \( k = 4 \).

Step 2 ：So, \( 4A = 4 \times \begin{bmatrix} 5 & 6 \\ 7 & 8 \end{bmatrix} = \begin{bmatrix} 4 \times 5 & 4 \times 6 \\ 4 \times 7 & 4 \times 8 \end{bmatrix} \)

Step 3 ：Simplify to get the final result matrix.