Hello, thank you for taking the time to post your question!
In each case you’re trying to get a line in the form y = mx + b, where “m” is the slope and then “b” is the y-intercept.
On the first one we have m = 0 , then you can plug in the point to find what the value of b is
y = mx + b
6 = 2(0) + b
6 = b
So the full equation is y = 0x + 6
On the second equation then you want to follow the same process, starting with m = 2 and plugging in the point (6,3)
y = 2x + b
3 = 2(6) + b
3 = 12 + b
-9 = b
making the full equation y = 2x - 9
I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)