Every time the unit sales price increases by 65,438+00 yuan, the annual sales volume will decrease by 65,438+00,000 yuan.

X- 100 Find out how much the unit price will increase.

(x- 100)/ 10 Find out the reduced sales.

Originally it was 200,000 yuan 100, so y = 20-(x- 100)/ 10 is calculated as y =-x/ 10+30.

(2)

Annual sales x*y

Production cost x*40

Because (annual profit = annual sales-production cost-investment)

z=xy-40x-500

Generation y goes in (note: x n represents the n power of x)

z=-x^2/ 10+30x-40x-500

Calculated z =-x y/ 10- 10x-500.

(3)

160 generation into x to find z.

Then return to the Z generation and find z =-x 2/ 10+30x-40x-500.

Find x (quadratic equation x has two solutions, one is 160, and the other is what we want).