Question

find an equation of the line that passes through the points (4,6) and (4,7)

Answer 1

first find slope
m=(7-6)/(4-4) =undefined
its vertical line because its slope is undefined.
equation of vertical line passing through point (a,b) is
x=a
here a=4
can you find it now ?

Answer 2

The slope : (7-6)/(4-4) = undefined which means there's no slope and the line is vertical.
The line passes through the points (4,6) and (4,7). the x coordinates of the both points = 4
Therefore, the equation is x=4

Answer 3

yes, thank you