Amahogany desk with a cash price of $810 is offered on the installment plan at $50 down and $58 per month for 15 months. what is the carrying charge?

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.