Answer:
slope = - 3
Step-by-step explanation:
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (1, 2) and (x₂, y₂ ) = (2, - 1) ← 2 points on the line
m = [tex]\frac{-1-2}{2-1}[/tex] = [tex]\frac{-3}{1}[/tex] = - 3
