Find the scale factor of a dilation

Divide an image coordinate by the matching original coordinate.

1. A dilation from the origin maps the point (4, 1) to (20, 5). What is the scale factor?
2. A dilation from the origin maps the point (6, −2) to (18, −6). What is the scale factor?
3. A dilation from the origin maps the point (−1, 6) to (−3, 18). What is the scale factor?
4. A dilation from the origin maps the point (6, −4) to (18, −12). What is the scale factor?
5. A dilation from the origin maps the point (3, −7) to (9, −21). What is the scale factor?
6. A dilation from the origin maps the point (−7, −1) to (−42, −6). What is the scale factor?
7. A dilation from the origin maps the point (1, −1) to (6, −6). What is the scale factor?
8. A dilation from the origin maps the point (4, −5) to (24, −30). What is the scale factor?
9. A dilation from the origin maps the point (4, 5) to (28, 35). What is the scale factor?
10. A dilation from the origin maps the point (−2, 3) to (−14, 21). What is the scale factor?
11. A dilation from the origin maps the point (1, 9) to (7, 63). What is the scale factor?
12. A dilation from the origin maps the point (1, −5) to (5, −25). What is the scale factor?
13. A dilation from the origin maps the point (−5, −2) to (−10, −4). What is the scale factor?
14. A dilation from the origin maps the point (5, 1) to (30, 6). What is the scale factor?
15. A dilation from the origin maps the point (−2, 1) to (−4, 2). What is the scale factor?
16. A dilation from the origin maps the point (−3, −8) to (−24, −64). What is the scale factor?
17. A dilation from the origin maps the point (−15, −2) to (−105, −14). What is the scale factor?
18. A dilation from the origin maps the point (2, −15) to (16, −120). What is the scale factor?
19. A dilation from the origin maps the point (−8, 3) to (−56, 21). What is the scale factor?
20. A dilation from the origin maps the point (14, −9) to (70, −45). What is the scale factor?