I multipled 42*28 and i got 1176
Revenue=quantity x price= (-2p+1000) (p)= -2p^2+1000p
The maximum revenue will occur when the first derivative is zero so when 2(-2p)+1000=0;p=250
Which generates 125,000 in revenue
Try prices of 245 and 255 and you will see they both are less than 250 thereby proving the max revenue is 250
Answer:
I need a graph paper and to record a video to show you this, but it's

Answer:
10.75 , 10 (6/24),13/20,-10(6/25)