The quantity demanded for a certain brand of portable CD players is 200 units when the unit price is set at $90. The quantity demanded is 1200 units when the unit price is $40. Find the demand price equation.

answer should be in the form p=mx+b, round to 2 decimal places if needed

Question

The quantity demanded for a certain brand of portable CD players is 200 units when the unit price is set at $90. The quantity demanded is 1200 units when the unit price is $40. Find the demand price equation. 

answer should be in the form p=mx+b, round to 2 decimal places if needed

anonymous · Answer

$$m = \frac{ \Delta y }{ \Delta x } = ($40 - $90) / (1200 - 200)  $$