The fixed costs of producing a good are 100 and the variable costs are2 + ????/10per unit. a)Find expressions for????????and????????. b)Evaluate????????at???? = 30and hence estimate the change...

The fixed costs of producing a good are 100 and the variable costs are2 +
????/10per unit.
a)Find expressions for????????and????????.
b)Evaluate????????at???? = 30and hence estimate the change in????????brought about
by a 2 unit increase in output from a current level of 30 units.
c)At what level of output does???????? = 22?