A factory has fixed costs of $1,275 per month. The cost of producing each unit of its product is $2.50. Each unit sells for $10.
The equations that model the cost and revenue for producing x units are shown.
      Cost: C(x) = 1275 + 2.5x
Revenue: R(x) = 10x
If the company sells every unit it produces, how many units must it sell in order to break even