C. Suppose that the allocatively efficient output level in long-run equilibrium is 210 meals. In long-run equilibrium,
suppose that this restaurant charges $11 per meal for 180 meals and that the marginal cost of the 180th meal is
$8. What is the size of the firm's economic profit?

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.