If the cost of manufacturing mobile phones is $10,000 for the factorytime plus $80 per phone and that each phone sells for $100, how many phones must be manufactured for the mobile phone manufacturer to
break even (when costs equals revenue)?

500 phones

Step-by-step explanation:

cost of manufacturing: y = 80x + 10,000

money from phone sales: y = 100x

* note: x = #phones

solve for when they're equal;

100x = 80x + 10,000

100x - 80x = 80x - 80x + 10,000

20x = 10,000      –––––––––––> divide both sides by 20

x = 500

answer:   c ?

step-by-step explanation: