ANSWER
The scale factor is 2.
EXPLANATION
The point H(7,9) is dilated about the origin and the image is (14,18).
Let the scale factor be k.
Then,
[tex](7,9)\to (7k,9k)[/tex]
Comparing to the given image, we have:
[tex] (7k,9k) = (14,18)[/tex]
This implies that,
[tex]7k = 14[/tex]
Divide by 2
[tex]k = 2[/tex]
Or
[tex]9k = 18[/tex]
[tex]k = 2[/tex]