Given:
Point A'(6,3) is a dilation of point A(18,9).
To find:
The scale factor.
Solution:
We know that, if a point P is dilated by factor k and origin is the center of dilation, then
![P(x,y)\to P'(kx,ky)](https://img.qammunity.org/2022/formulas/mathematics/high-school/9wog3bszkyfl4g7gksw8kjxwd2r6pafv6x.png)
Let the scale factor for the given problem be k. So,
![A(18,9)\to A'(18k,9k)](https://img.qammunity.org/2022/formulas/mathematics/high-school/inerabhem4udlq8i3juhjncqyf5jc6ehtb.png)
On comparing A'(18k,9k) and A'(6,3), we get
![18k=6\text{ and }9k=3](https://img.qammunity.org/2022/formulas/mathematics/high-school/4rn95cwoxduncxyuwj8ac07u3kw5elpia4.png)
![k=(6)/(18)\text{ and }k=(3)/(9)](https://img.qammunity.org/2022/formulas/mathematics/high-school/ktnz6egd6pcan38i2lcq44t3ds29skc624.png)
![k=(1)/(3)\text{ and }k=(1)/(3)](https://img.qammunity.org/2022/formulas/mathematics/high-school/aya3cchx6prclybfeqbmfuuqs9411168e9.png)
Therefore, the scale factor is
.