Answer:
Your slope is -133 1/3
Explanation:
slope intercept form: 
slope (m) = (y₂ - y₁)/(x₂ - x₁) 
Let: 
(x₁ , y₁) = (3 , 1200)
(x₂ , y₂) = (6 , 800)
Plug in the corresponding numbers to the corresponding variables: 
m = (800 - 1200)/(6 - 3)
Simplify. Remember to follow PEMDAS. First solve the parenthesis, then divide: 
m = (-400)/(3)
m = ~-133 1/3
Your slope is -133 1/3.
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