13. 11 = 2b +17 14. 5 = 4a -7 16. 2g - 3= -19 17. 16 = 5x - 9 19. 5 + y/8 = -3 20. 3 - 8c = 35 22. - 1/2x - 7 = -11 23. 15 - w/4 = 28

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.