Please help ?

Prove that the diagonals of a rectangle bisect each other.
Name the coordinates for point C.

A: (b, a)

B: (2a, 2b)

C: (a, b)

D: (2b, 2a)

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.