Answer:
[tex]Q_n=(2000)-(20)P_n[/tex]
Step-by-step explanation:
From the question we are told that:
Initial Quantity demanded Q_1= 200 units
Initial demand price [tex]P_1=\$90[/tex]
Final Quantity demanded [tex]Q_2= 1200 units[/tex]
Final demand price [tex]P_2=\$40[/tex]
Generally the Demand Equation is mathematically given by
[tex]Q_n=a-bP_n[/tex]
Where
a=Other factors affecting price
b=Slope of the demand curve
Therefore
[tex]Q_1=a-bP_1[/tex]
[tex]200=a-b(90)[/tex]
[tex]Q_2=a-bP_2[/tex]
[tex]1200=a-b(40)[/tex]
Comparing both above equations
[tex]a=2000[/tex]
[tex]b=20[/tex]
Therefore the Demand Equation is mathematically given by
[tex]Q_n=(2000)-(20)P_n[/tex]