A company manufactures cell phones and sells them for $\$150$ each. The fixed costs of producing the cell phones are $\$56,000$ plus a variable cost of $\$45$ for each cell phone produced. Let $x$ be the number of cell phones produced.
$(1)$ Let $C(x)$ be the cost function. Find $C(x)$.
$(2)$ Let $R(x)$ be the revenue function. Find $R(x)$.
$(3)$ Let $P(x)$ be the profit function. Find $P(x)$ in terms of $x$
$(4)$ What is the profit if $50,000$ cell phones are sold?
$(5)$ Find the break even point.
I'm sort of confused on how to set up the functions, and what is a break even point? What do they mean by "variable cost" and "fixed cost".
Any sort of help would be great. Including answers!