Answer:
[tex]\displaystyle 6[/tex]
Step-by-step explanation:
[tex]\displaystyle \frac{-y_1 + y_2}{-x_1 + x_2} = m \\ \\ \frac{-3 + 9}{-1 + 2} = m; \boxed{6 = m}[/tex]
I am joyous to assist you at any time.