Answer:
(18 is wrong, the slope is 1/3)
Explanation:
Using the equation in the top right
11.) (-10-(-4))/(-12-(-20))= -(3/4)
12.) (-8+5)/(0+12)= -(1/4)
13.) (16-(-6))/(15-(-19))= (11/17)
14.) (-9-9)/(7+6)= -(18/13)
15.) (-15+20)/(-18+18)= No solution
16.) (12+18)/(11-12) = -30