Can someone pls help?

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.

Find two numbers if their sum is 91 and the ratio is 6: 7?

The sum of 5consecutive even numbers is 100. what is the first number in this sequence?