It is a straight line so it will be in the form: y = mx + b
Slope = m = (change in y) / (change in x)
m = (6-6) / (1-7) = 0
The slope is zero so it is just a horizontal line. (with no slope)
Notice that both of the y-values are 6.
The line is a horizontal line, going through those two points, where y = 6.
In slope-intercept form: y = 0x + 6
Or simply: y = 6