csat-suneung 2012 Q1

csat-suneung · South-Korea · csat__math-science 2 marks Matrices Linear System and Inverse Existence
The sum of all components of the inverse matrix $A ^ { - 1 }$ of the matrix $A = \left( \begin{array} { r r } 1 & - 2 \\ 0 & 1 \end{array} \right)$ is? [2 points]
(1) 5
(2) 4
(3) 3
(4) 2
(5) 1
The sum of all components of the inverse matrix $A ^ { - 1 }$ of the matrix $A = \left( \begin{array} { r r } 1 & - 2 \\ 0 & 1 \end{array} \right)$ is? [2 points]\\
(1) 5\\
(2) 4\\
(3) 3\\
(4) 2\\
(5) 1