Renata raked x piles of leaves dylan raked 2/3 times the number of piles renata did. Together they raked 15 piles of leaves. Write an equation to represent this situation

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.