Number 10 please I don’t know how to do it and if you could also do 11

Answer:
Step-by-step explanation:
x = 1, y = 12
x = 2, y = 9
x = 3, y = 6
x = 4, y = 3
The formula of a slope:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\dfrac{9-12}{2-1}=\dfrac{-3}{1}=-3[/tex]