Select the correct answer.

If [tex][tex]$A=\left[\begin{array}{rrr}2 & 4 & -2 \\ 4 & -5 & 7 \\ 2 & 7 & 5\end{array}\right]$[/tex][/tex] and [tex][tex]$A B=\left[\begin{array}{r}24 \\ -46 \\ -2\end{array}\right]$[/tex][/tex], what is the value of matrix [tex][tex]$B$[/tex][/tex]?

A. [tex][tex]$B=\left[\begin{array}{c}2 \\ 3 \\ -7\end{array}\right]$[/tex][/tex]
B. [tex][tex]$B=\left[\begin{array}{c}1 \\ 2 \\ -7\end{array}\right]$[/tex][/tex]
C. [tex][tex]$B=\left[\begin{array}{r}1 \\ 3 \\ -5\end{array}\right]$[/tex][/tex]
D. [tex][tex]$B=\left[\begin{array}{r}2 \\ 2 \\ -5\end{array}\right]$[/tex][/tex]



Answer :

To find the value of matrix [tex]\( B \)[/tex], we need to solve the system of linear equations given by [tex]\( A B = \left[\begin{array}{r}24 \\ -46 \\ -2\end{array}\right] \)[/tex].

Given the matrix [tex]\(A\)[/tex] and the result of matrix multiplication [tex]\(AB\)[/tex]:
[tex]\[ A = \left[\begin{array}{rrr} 2 & 4 & -2 \\ 4 & -5 & 7 \\ 2 & 7 & 5 \end{array}\right] \][/tex]
and
[tex]\[ A B = \left[\begin{array}{r} 24 \\ -46 \\ -2 \end{array}\right] \][/tex]

The system of linear equations represented by [tex]\(A B = \left[\begin{array}{r}24 \\ -46 \\ -2\end{array}\right]\)[/tex] corresponds to finding [tex]\( B \)[/tex] such that:
[tex]\[ \left[\begin{array}{rrr} 2 & 4 & -2 \\ 4 & -5 & 7 \\ 2 & 7 & 5 \end{array}\right] \left[\begin{array}{r} b_1 \\ b_2 \\ b_3 \end{array}\right] = \left[\begin{array}{r} 24 \\ -46 \\ -2 \end{array}\right] \][/tex]

By solving these linear equations, we obtain:
[tex]\[ B = \left[\begin{array}{r}1 \\ 3 \\ -5\end{array}\right] \][/tex]

Therefore, the correct answer is:
C. [tex]\( B = \left[\begin{array}{r}1 \\ 3 \\ -5\end{array}\right] \)[/tex]