Problema Solution

1. supposeacell phone servicecosts$45 per month, along with a$60 activation fee.

a. Write a costequationthat relates the number of months of serviceand the total cost for that time of service.(hint: Let t= the number of months of service and c= the total cost of $1,185.

2. Your company has determined that the profit equation (in thousands of dollars)+ of producing x thousand smartphones is as follows:

Profit=-x2 +110x -1,000

Ifthe number of smartphones is 40,000, for example, then x= 40). The break-even point is the number of smartphones sold and produced that would result in a profit of zero. Use your preferred method for solving the quadratic equation to determine the break-even point.

Answer provided by our tutors

1a.  c = 45t + 60

2.  Break-even point: -x^2 + 110x - 1000 = 0

This can be factorised:  (-x+100)(x-10)=0

solutions x=10, x=100.  So break-even point is either 10,000 or 100,000 smartphones.