3 and 4 .Determinants and Matrices
easy

$\left| {\,\begin{array}{*{20}{c}}4&{ - 6}&1\\{ - 1}&{ - 1}&1\\{ - 4}&{11}&{ - 1\,}\end{array}} \right|= . . . $

A

$-75$

B

$25$

C

$0$

D

$-25$

Solution

(d) $\left| {\,\begin{array}{*{20}{c}}4&{ – 6}&1\\{ – 1}&{ – 1}&1\\{ – 4}&{11}&{ – 1}\end{array}\,} \right| = \left| {\,\begin{array}{*{20}{c}}0&5&0\\{ – 1}&{ – 1}&1\\{ – 4}&{11}&{ – 1}\end{array}\,} \right|$    $\{ {\rm{Apply }}{R_{\rm{1}}} \to {R_1} + {R_3}\} $

= $ – 5\,(1 + 4) = – 25$.

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.