[填空题]
Parallelogram ABCD +3 a bk7c,b(lngm.wgs iei+yl1w 2 c.b3 cv g6jjzcog+1s translated by the vector $\left(\begin{array}{l}1 \\ 4\end{array}\right)$ , then enlarged by a scale factor of $\frac{3}{2} $ from the origin and then reflected in the y -axis.
1. Determine a single transformation that maps the parallelogram A B C D to its image. Give your answer in the form
$\mathbf{x}^{\prime}=\mathbf{A} \mathbf{x}+\mathbf{b} \text {. }$
The area of the image is equal to k times the area of parallelogram A B C D .
2. Find the value of k .$\frac{a}{b}$a = b =