If A = | , * 20 c - 1 &2&4 3&1&0 - 2 &4&2 , |and B = | , * 20 c -… - Vidyadip

MCQ

If $A = \left| {\,\begin{array}{*{20}{c}}{ - 1}&2&4\\3&1&0\\{ - 2}&4&2\end{array}\,} \right|$and $B = \left| {\,\begin{array}{*{20}{c}}{ - 2}&4&2\\6&2&0\\{ - 2}&4&8\end{array}\,} \right|$, then $B$ is given by

A
$B = 4A$
✓
$B = - 4A$
C
$B = - A$
D
$B = 6A$

✓

Answer

Correct option: B.

$B = - 4A$

b
(b) $B$ is obtained from $A$ by the operations ${R_1} \leftrightarrow {R_3},\,\,{R_3} \to 2{R_3}$ and ${R_2 → 2R_2}.$
Hence, $B = ( - 1)\,4A = - 4A$.

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