
Tamara J. answered 05/12/13
Math Tutoring - Algebra and Calculus (all levels)
Recall: Profit = Revenue - Cost
P(x) = R(x) - C(x) , where x is the number of pizzas sold
Revenue, R(x), is given by the following:
R(x) = (selling price)·(# of pizzas sold)
R(x) = 12x
Cost, C(x), is given by the following:
C(x) = (variable cost)·(# of pizzas sold) + fixed cost
C(x) = 5x + 230
Therefore, since Profit = Revenue - Cost
P(x) = R(x) - C(x)
P(x) = 12x - (5x + 230)
P(x) = 12x - 5x - 230
P(x) = 7x - 230
Thus, the profit of selling 85 pizzas is determined by solving P(x) when x=85:
P(x) = 7x - 230
P(85) = 7(85) - 230
= 595 - 230
= 365
Since P(85) = 365 , selling 85 pizzas yield a profit of $365.
To find how many pizzas need to be sold to yield a profit of $700, solve for x when P(x)=700:
P(x) = 7x - 230
700 = 7x - 230
700 + 230 = 7x - 230 + 230
930 = 7x
930/7 = 7x/7
132.86 = x
x ≈ 133
Thus, to make a profit of $700, 133 pizzas need to be sold.
To find how many pizzas need to be sold to yield a profit greater than $1000, solve for x when P(x)>1000:
P(x) = 7x - 230
7x - 230 > 1000
7x - 230 + 230 > 1000 + 230
7x > 1230
7x/7 > 1230/7
x > 175.7
x ≥ 176
Thus, to make a profit greater than $1000, you would need to sell at least 176 pizzas.