find slope must shpw work

when given two points on a line, the easiest way to calculate the slope is take the difference of the y in point 1 minus y in point 2 and divide that by the differences of the x's

m - slope

p

_{1}- (-6,-9) ⇒ x_{1}= -6 and y_{1}= -9p

_{2}- (-6,6) ⇒ x_{2}= -6 and y_{2}= 6m = (y

_{1}-y_{2})/(x_{1}-x_{2})Substituting in the values for x

_{1}, x_{2}, y_{1}, y_{2}you get

m = ((-9)-6)/((-6)-(-6)) = -15/(-6+6) = -15/0 ⇒ undefined

hmm but we can't divide by zero, which is of course why this slope value is "undefined"

This is a unique line that is vertical or parallel to the y-axis