Please answer questions 3 and 4 (for question 4 section D the equation is h(x)=g(x)/f(x)+g(x) ) I know in The photo the plus looks like a minus for that equation

3. The cost (in dollars) of producing x units of a certain commodity is (x) - 100 + 50x -0.02.r2 (a) Find the average rate of change of C with respect to x when the production level is changed from x =100 to 105 (b) Find the instantaneous rate of change of C with respect to x when x =100 and interpret the value of it. Suppose that /(4) - 2. g(4) -5, /(4) -6, and g (= =3. Find derivative " (1) in (a) - (d). (a) hix) =3/ (x) - Bg(x)