Answer:
0x + y = 6
Explanation:
Equation of the Line
The equation of a line passing through points (x1,y1) and (x2,y2) can be written as follows:

It can be later converted to any other form of the line. For example, the standard form is:

Let's find the equation by using the given points (0,6) (5,6):

Operating:

y - 6 = 0
Or, equivalently:
0x + y = 6
This corresponds to a horizontal line