Question 1155517
The formula for profit is {{{P(x)= -x^2+980x-3000}}}

At the value of x where this function (profit) is maximum, the first derivative of the formula will be 0. 

i.e. {{{-2x + 980 = 0}}}

or {{{x = 980 / 2 = 490}}}

490 virtual pets will yield the maximum profit.

The maximum profit can be found by substituting x = 490 in the formula

Max profit = P(490) = {{{-(490^2) + 980x490 - 3000 = 237100}}}

Ans: 490 pets, profit $237100