Question

IF A=[ 2/-1 3/5],then find 2A-3I​

Answer 1

$\sf A = \left [\begin{array}{cc}2&3\\ - 1&5 \end{array} \right]$

$\sf \purple{we \: know}$

$\sf I= \left [\begin{array}{cc}1&0\\ 0&1 \end{array} \right]$

$\implies \sf2 \left [\begin{array}{cc}2&3\\ - 1&5 \end{array} \right] - 3\left [\begin{array}{cc}1&0\\ 0&1 \end{array} \right]$

$\implies \sf \left [\begin{array}{cc}4&6\\ - 2&10 \end{array} \right] - \left [\begin{array}{cc}3&0\\ 0&3 \end{array} \right]$

$\orange{ \sf \therefore2A - 3I = \sf \left [\begin{array}{cc}1&6\\ - 2&7 \end{array} \right] }$

HOPE IT HELPS!!