If $\left[ {\begin{array}{*{20}{c}} {2\;\,\,\;1}\\ {3\;\;\,2} \end{array}} \right]A\left[ {\begin{array}{*{20}{c}} { - 3\;\;\;\;\;\;\;2}\\ {5\;\;\;\;\, - 3} \end{array}} \right] = \left[ {\begin{array}{*{20}{c}} {1\;\;\,\,0}\\ {0\;\;\,\,1} \end{array}} \right],\;$ then $A$ is equal to

$\left[ {\begin{array}{*{20}{c}} {1\;\;\,\,\,0}\\ {1\;\,\,\,\,\;1} \end{array}} \right]$

$ - \left[ {\begin{array}{*{20}{c}} {1\;\,\,\,\,\;1}\\ {1\;\;\,\,0} \end{array}} \right]$

$\left[ {\begin{array}{*{20}{c}} {1\;\;\,\,\,1}\\ {0\;\;\,\,1} \end{array}} \right]$

$\left[ {\begin{array}{*{20}{c}} {0\;\;\,\,\,1}\\ {1\;\,\,\,\,\;1} \end{array}} \right]$

JEE MATHEMATICS MCQ: MATRICES

1 Easy

1 of 1

Application +4 | -1

\left[ {\begin{array}{cccccccccccccccccccc} {2\;\,\,\;1}\\ {3\;\;\,2} \end{array}} \right]A\left[ {\begin{array}{cccccccccccccccccccc} { - 3\;\;\;\;\;\;\;2}\\ {5\;\;\;\;\, - 3} \end{array}} \right] = \left[ {\begin{array}{cccccccccccccccccccc} {1\;\;\,\,0}\\ {0\;\;\,\,1} \end{array}} \right],\;

then

A

is equal to

View answer and explanation

Correct option: C

\left[ {\begin{array}{cccccccccccccccccccc} {1\;\;\,\,\,0}\\ {1\;\,\,\,\,\;1} \end{array}} \right]

The correct answer is C. By pre-multiplying and post-multiplying by the inverses of the given matrices, we can isolate A and find its value.