If $A=\left[\begin{array}{cc}0 & 2 \\ 3 & -4\end{array}\right]$ and $k A=\left[\begin{array}{cc}0 & 3 a \\ 2 b & 24\end{array}\right]$, then $(k, a, b)=$_______
It is given that, $A=\left[\begin{array}{cc}0 & 2 \\ 3 & -4\end{array}\right]$ and $k A=\left[\begin{array}{cc}0 & 3 a \\ 2 b & 24\end{array}\right]$.
$\therefore k\left[\begin{array}{cc}0 & 2 \\ 3 & -4\end{array}\right]=\left[\begin{array}{cc}0 & 3 a \\ 2 b & 24\end{array}\right]$
$\Rightarrow\left[\begin{array}{cc}0 & 2 k \\ 3 k & -4 k\end{array}\right]=\left[\begin{array}{cc}0 & 3 a \\ 2 b & 24\end{array}\right]$
$\Rightarrow 3 a=2 k, 2 b=3 k$ and $-4 k=24$
Now,
$-4 k=24 \Rightarrow k=-6$
$\therefore 3 a=2 k$
$\Rightarrow 3 a=2 \times(-6)=-12$
$\Rightarrow a=-4$
Also,
$2 b=3 k$
$\Rightarrow 2 b=3 \times(-6)=-18$
$\Rightarrow b=-9$
Thus, $(k, a, b)=(-6,-4,-9)$
If $A=\left[\begin{array}{cc}0 & 2 \\ 3 & -4\end{array}\right]$ and $k A=\left[\begin{array}{cc}0 & 3 a \\ 2 b & 24\end{array}\right]$, then $(k, a, b)=\underline{-(-6,-4,-9)}$.