Answer:
slope = 1
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 ) = (6, - 12 ) and (x₂, y₂ ) = (15, - 3 )
m = [tex]\frac{-3-(-12)}{15-6}[/tex] = [tex]\frac{-3+12}{9}[/tex] = [tex]\frac{9}{9}[/tex] = 1