A basic cellular package costs $30/month for 60 minutes of calling with an additional charge of $0.40/minute beyond that time. The cost function C(x) for using x minutes would be If you used 60 minutes or less, i. e. if if x≤60,  then C(x)=30 (the base charge). 

If you used more than 60 minutes, i. e. (x−60) minutes more than the plan came with, you would pay an additional $0.40 for each of those (x−60) minutes. Your total bill would be C(x)=30+0.40(x−60).

 
If you want to keep your bill at $50 or lower for the month, what is the maximum number of calling minutes you can use?
 
The maximum calling minutes you can use is   minutes.
 

Browning labs is testing a new growth inhibitor for a certain type of bacteria. the bacteria naturally grows exponentially each hour at a rate of 6.2%. the researchers know that the inhibitor will make the growth rate of the bacteria less than or equal to its natural growth rate. the sample currently contains 100 bacteria.the container holding the sample can hold only 300 bacteria, after which the sample will no longer grow. however, the researchers are increasing the size of the container at a constant rate allowing the container to hold 100 more bacteria each hour. they would like to determine the possible number of bacteria in the container over time.create a system of inequalities to model the situation above, and use it to determine how many of the solutions are viable.

If a is a nonzero real number then the reciprocal of a is

What is r i 4.5+10r=-6.5 with work pls