The general form of the line is y = mx + c
where m is the slope and c is y-intercept
Using the given points (-4, 3) and (-4 , 7)
So, the slope will be calculated as following:
it is not logic to divide by zero
so, the slope is undefined which mean the line passing through
the points (-4 , 3 ) and (-4 , 7) is parallel to y-axis
and the equation of this line is x = -4
So, slope is undefined