You guys, I seriously need help with this! I have been working on this for like 5 hours and I still can't understand it! Please put an explanation!

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.