Answer: scroll down to find out :)
Explanation:
This isn't a hard equation, so I would just use the points and figure something out.
Some obvious points are (3, 6), (6, 12), and (7, 14). Immediately, we notice that the y coordinate is 2 times the x coordinate.
So, the equation would be y = 2x.
P.S. Let me know if I got it wrong! I'll be more than happy to fix it :)