Help pls thank you very much

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.

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14

What is the product? a-3/15a × 5/a-3