Verified Answer :

-20 - (-8) = -12
-12 - (-3) = -9

-12/-9 = -4/-3

slope= -4/3

Answer: \(\dfrac{4}{3}\ or\ 1\dfrac{1}{3}\)

Step-by-step explanation:

The slope of a line that passes through two points (a,b) and (c,d) is given by :-

\(m=\dfrac{d-b}{c-a}\)

Then, the  slope of a line that passes through two points (-3,-8) and (-12,-20) will be :-

\(m=\dfrac{-20-(-8)}{-12-(-3)}\\\\\Rightarrow\ m=\dfrac{-(20-8)}{-(12-3)}\ \ \text{[By using distributive property]}\\\\\Rightarrow\ m=\dfrac{-(12)}{-(9)}\\\\\Rightarrow\ m=\dfrac{12}{9}=\dfra{3\times4}{3\times 3}\\\\\Rightarrow\ m=\dfrac{4}{3}\)

Hence, the slope of a line that passes through two points (-3,-8) and (-12,-20) =\(\dfrac{4}{3}\ or\ 1\dfrac{1}{3}\)