∫∫D(x2 + y2 + 2020)dxdy D: x2 +y2 +2ax ≤ 0 (a > 0)

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.