Estimate 349.6-112.8 to find the correct answer

Which of the following is not a subset of {1,2,3}?

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.

Solve 17= -13 - 8x and show your work.