Find the slope if it exsist of the line containing the pair

Solution

( - 9 , -19 ) and ( -15 , - 20 )

slope is change in y over change in x

slope = y2 - y1 / x2 - x1

plugging the values in the formula

slope = -20 - (-19) / -15 - (-9)

= -20 + 19 / -15 + 9

= -1 / -6

hence

slope = 1/6