when r = c is the break even point.
since r = 14x and c = 12x + 36000, then the break even point is when 14x = 12x + 36000
subtract 12x from both sides of this equation to get 14x - 12x = 36000.
combine like terms to get 2x = 36000.
divide both sides of this equation by 2 to get x = 18000.
that'a our answer.
the revenue will be equal to the cost when 18000 units are sold.
revenue = 14 * 18000 = 252000.
cost = 12 * 18000 + 36000 = 252000.