ANSWER
[tex]\begin{gathered} (a)48\text{ sq units} \\ (b)300\text{ sq units} \end{gathered}[/tex]
EXPLANATION
When a shape is dilated by a scale factor k, its area dilates quadratically. In other words, the area dilates by:
[tex]k^2[/tex]
This means that to find the area of the new shapes after dilation, we have to multiply the original area by the square of k.
(a) For k = 2, the area becomes:
[tex]\begin{gathered} A=12\cdot2^2 \\ A=12\cdot4 \\ A=48\text{ sq units} \end{gathered}[/tex]
(b) For k = 5, the area becomes:
[tex]\begin{gathered} A=12\cdot5^2 \\ A=12\cdot25 \\ A=300\text{ sq units} \end{gathered}[/tex]
