An electron manufacturer sells headphones for $157.

a) write down the equation to find the income i when n headphones are sold.

b) the fixed cost of production is $5000 per year. the variable cost is $43 per headphone. write down the equation to fin the cost c of producing n headphones.

c) how many headphones must be sold to break even?

d) write down the equation linking the manufacturer’s profit, and the number of headphones sold n.

e) how many must be sold to make a profit of $2?