What does DNE mean as an answer for this question.
(12,10) (12,5) Find the slope of a line that passes through each pair of points.
It means that the slope Does Not Exist [D.N.E.]......a better term is to say that the slope is undefined.....to see why, note....
slope = [ 5 - 10] / [ 12 - 12] = -5/0 but....we can't divide by 0 ... [ this is undefined]
The equation for this line is x = 12 The slope is 'undefined'
+42 
