​ If (2A – B) = ((6,-6,0),(-4,2,1)) and (2B + A) = ((3,2,5),(-2,1,-7)) then A = ? ​

Question

If (2A – B) = \( ​​​​\begin{pmatrix} 6 & -6&0 \\ -4 & 2&1 \\ \end{pmatrix} \)and (2B + A) = \( ​​​​\begin{pmatrix} 3 & 2&5 \\ -2 & 1&-7 \\ \end{pmatrix} \)then A = ?

A. \( ​​​​\begin{pmatrix} -3 & 2&1 \\ 2 & 1&-1 \\ \end{pmatrix} \)

B. \( ​​​​\begin{pmatrix} -3 & 2&-1 \\ 2 & -1&1 \\ \end{pmatrix} \)

C. \( ​​​​\begin{pmatrix} 3 & -2&1 \\ - 2 & 1&-1 \\ \end{pmatrix} \)

D. none of these

Answer 1

(2A – B) = \( ​​​​\begin{pmatrix} 6 & -6&-0 \\ -4 & 2&1 \\ \end{pmatrix} \)

Multiplying by 2

Dividing each element of the matrix by 5

A = \( ​​​​\begin{pmatrix} 3 & 2&1 \\ -2 & 1&-1 \\ \end{pmatrix} \)