**4.4 Pendaraban Matriks dengan Nombor (Contoh Soalan)**

**Contoh 1:**

Ungkapkan setiap yang berikut sebagai satu matriks tunggal.

$\text{(a)}3\left(\begin{array}{cc}1& -4\\ -3& 2\end{array}\right)+2\left(\begin{array}{cc}-3& 1\\ 3& -4\end{array}\right)$

$\text{(b)}2\left(\begin{array}{cc}-1& 0\\ 9& -4\end{array}\right)-4\left(\begin{array}{cc}-2& 2\\ 3& -6\end{array}\right)-\frac{1}{3}\left(\begin{array}{cc}-9& -3\\ -6& 15\end{array}\right)$

*Penyelesaian:*$\begin{array}{l}\text{(b)}2\left(\begin{array}{cc}-1& 0\\ 9& -4\end{array}\right)-4\left(\begin{array}{cc}-2& 2\\ 3& -6\end{array}\right)-\frac{1}{3}\left(\begin{array}{cc}-9& -3\\ -6& 15\end{array}\right)\\ =\left(\begin{array}{cc}-2& 0\\ 18& -8\end{array}\right)-\left(\begin{array}{cc}-8& 8\\ 12& -24\end{array}\right)-\left(\begin{array}{cc}\frac{1}{3}\times (-9)& \frac{1}{3}\times (-3)\\ \frac{1}{3}\times (-6)& \frac{1}{3}\times 15\end{array}\right)\\ =\left(\begin{array}{cc}-2& 0\\ 18& -8\end{array}\right)-\left(\begin{array}{cc}-8& 8\\ 12& -24\end{array}\right)-\left(\begin{array}{cc}-3& -1\\ -2& 5\end{array}\right)\\ =\left(\begin{array}{cc}-2-(-8)-(-3)& 0-8-(-1)\\ 18-12-(-2)& -8-(-24)-5\end{array}\right)\\ =\left(\begin{array}{cc}9& -7\\ 10& 11\end{array}\right)\end{array}$