Summer spent $55.60 on clothes before sales tax. if sales tax is 7.5%, what did summer spend with tax included?   *add explanation if u can*

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.