Answer:
-30
Step-by-step explanation:
[tex]\boxed{slope = \frac{y1 - y2}{x1 - x2} }[/tex]
where (x₁, y₁) is the first coordinate and (x₂, y₂) is the second coordinate.
Slope
[tex] = \frac{12 - ( - 18)}{11 - 12} [/tex]
[tex] = \frac{12 + 18}{ - 1} [/tex]
= -30