2922.sagews

x = var('x')
price = 100-(0.01*x)

R = x*price
C = 50*x + 10000
P = R - C
dP = diff(P,x)
solve(dP == 0, x)

[x == 2500]

P(x=2500)

52500.0000000000

price(x=2500)

75.0000000000000

CI = C + 10*x
PI = R - CI

dPI = diff(PI,x)
solve(dPI == 0, x)

[x == 2000]

PI(x=2000)

30000.0000000000

price(x=2000)

80.0000000000000