PLEASE HELP !? NEED SOME HELP WITH THIS QUESTION THANKS !

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.

If f(x) = 3x-2 and g(x) =2x+1 find (f-g)(x)

What is the definition of a surd.give an example.