Idon't really understand my math homework. it's solving problems using equations.

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.

The measures of two supplementary angles are (2x + 10)° and (8x + 10)°. what is the measure of the larger angle? a. 16° b. 44° c. 14° d. 138°

For which rational expression is -2 an excluded value of x