Find the inverse of the matrix, if it exists
-$A = \left[ \begin{array} { r r } - 5 & - 5 \ 2 & 2 \end{array} \right]$
A) A is not invertible
B)
$$\left[ \begin{array} { c c }
\frac { 2 } { 21 } & \frac { 5 } { 21 } \
- \frac { 2 } { 21 } & - \frac { 5 } { 21 }
\end{array} \right]$$
C)
$$\left[ \begin{array} { c c }
- \frac { 2 } { 21 } & - \frac { 5 } { 21 } \
\frac { 2 } { 21 } & \frac { 5 } { 21 }
\end{array} \right]$$
D)
$$\left[ \begin{array} { l }
\frac { 2 } { 21 } - \frac { 5 } { 21 } \
\frac { 2 } { 21 } - \frac { 5 } { 21 }
\end{array} \right]$$

Question

Find the inverse of the matrix, if it exists
-$A = \left[ \begin{array} { r r } - 5 & - 5 \ 2 & 2 \end{array} \right]$
A) A is not invertible
B)
$$\left[ \begin{array} { c c } 
\frac { 2 } { 21 } & \frac { 5 } { 21 } \
- \frac { 2 } { 21 } & - \frac { 5 } { 21 }
\end{array} \right]$$
C)
$$\left[ \begin{array} { c c } 
- \frac { 2 } { 21 } & - \frac { 5 } { 21 } \
\frac { 2 } { 21 } & \frac { 5 } { 21 }
\end{array} \right]$$
D)
$$\left[ \begin{array} { l } 
\frac { 2 } { 21 } - \frac { 5 } { 21 } \
\frac { 2 } { 21 } - \frac { 5 } { 21 }
\end{array} \right]$$

Quizplus · Accepted Answer

The determinant of matrix $A$ is $0$ ($(-5)(2) - (-5)(2) = 0$), which means the matrix is not invertible.

Find the Inverse of the Matrix, If It Exists - A=[−5−522]A = \left[ \begin{array} { r r } - 5 & - 5 \\ 2 & 2 \end{array} \right]A=[−52​−52​]

Find the Inverse of the Matrix, If It Exists
- $A = \left[ \begin{array} { r r } - 5 & - 5 \\ 2 & 2 \end{array} \right]$