Select the correct answer.

If [tex]$A=\left[\begin{array}{cc}5 & -8 \\ 3 & 0\end{array}\right]$[/tex] and [tex]$B=\left[\begin{array}{cc}2 & -9 \\ 1 & 0\end{array}\right]$[/tex], which matrix is the result of [tex][tex]$2A - 3B$[/tex][/tex]?

A. [tex]$\left[\begin{array}{cc}4 & 11 \\ 3 & 0\end{array}\right]$[/tex]
B. [tex]$\left[\begin{array}{cc}4 & 38 \\ 9 & 0\end{array}\right]$[/tex]
C. [tex][tex]$\left[\begin{array}{cc}4 & 11 \\ 9 & 0\end{array}\right]$[/tex][/tex]
D. [tex]$\left[\begin{array}{cc}1 & -18 \\ 1 & 0\end{array}\right]$[/tex]



Answer :

To solve for [tex]\(2A - 3B\)[/tex], let's break down the computation step by step.

1. Define the matrices [tex]\(A\)[/tex] and [tex]\(B\)[/tex]:
[tex]\[ A = \begin{pmatrix} 5 & -8 \\ 3 & 0 \end{pmatrix} \][/tex]
[tex]\[ B = \begin{pmatrix} 2 & -9 \\ 1 & 0 \end{pmatrix} \][/tex]

2. Calculate [tex]\(2A\)[/tex]:
[tex]\[ 2A = 2 \cdot \begin{pmatrix} 5 & -8 \\ 3 & 0 \end{pmatrix} = \begin{pmatrix} 2 \cdot 5 & 2 \cdot -8 \\ 2 \cdot 3 & 2 \cdot 0 \end{pmatrix} = \begin{pmatrix} 10 & -16 \\ 6 & 0 \end{pmatrix} \][/tex]

3. Calculate [tex]\(3B\)[/tex]:
[tex]\[ 3B = 3 \cdot \begin{pmatrix} 2 & -9 \\ 1 & 0 \end{pmatrix} = \begin{pmatrix} 3 \cdot 2 & 3 \cdot -9 \\ 3 \cdot 1 & 3 \cdot 0 \end{pmatrix} = \begin{pmatrix} 6 & -27 \\ 3 & 0 \end{pmatrix} \][/tex]

4. Calculate [tex]\(2A - 3B\)[/tex]:
[tex]\[ 2A - 3B = \begin{pmatrix} 10 & -16 \\ 6 & 0 \end{pmatrix} - \begin{pmatrix} 6 & -27 \\ 3 & 0 \end{pmatrix} = \begin{pmatrix} 10 - 6 & -16 - (-27) \\ 6 - 3 & 0 - 0 \end{pmatrix} = \begin{pmatrix} 4 & 11 \\ 3 & 0 \end{pmatrix} \][/tex]

Thus, the result of [tex]\(2A - 3B\)[/tex] is:
[tex]\[ \begin{pmatrix} 4 & 11 \\ 3 & 0 \end{pmatrix} \][/tex]

Therefore, the correct answer is:
A. [tex]\(\left[\begin{array}{cc}4 & 11 \\ 3 & 0\end{array}\right]\)[/tex]