hello. I hope your day was fine and have some difficulties in the three question I just took a picture of please help me

Ineed me i stuck and i don’t want to get it wrong

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.

A10 inch cookie cake is divided into 8 slices. what is the area of 3 slices