Given:
The triangle ABC and A'B'C' on a coordinate plane.
To find:
The algebraic rule that describes the dilation of ABC to A'B'C.
Solution:
From the given figure it is clear that
AB = 2 units
A'B' = 6 units
The scale factor is
![k=(A'B')/(AB)](https://img.qammunity.org/2022/formulas/mathematics/high-school/eo9e5jhn93ycyzwrm8dmxs0lgegc9m5bsb.png)
![k=(6)/(2)](https://img.qammunity.org/2022/formulas/mathematics/high-school/bsnqkokpk05p9nraaxq7rxd4ie07v1o8a2.png)
![k=3](https://img.qammunity.org/2022/formulas/mathematics/high-school/dmza7ig8f4b23ym9i4osga40mcp4qo7xop.png)
So, the scale factor is 3.
If a figure is dilated about the origin with scale factor k, then the rule of dilation is
![(x,y)\to (kx,ky)](https://img.qammunity.org/2022/formulas/mathematics/high-school/e3lacytewqtltsvoqbo5laayjcqqy00l4a.png)
For the given problem the scale factor is 3. So, putting k=3, we get
![(x,y)\to (3x,3y)](https://img.qammunity.org/2022/formulas/mathematics/high-school/qwxpfkmjgbrwxsthvlsku3d31h5rnt6in8.png)
Therefore, the correct option is A.