Does this firms production process exhibit cost

Question

Consider a firm that produces two products. The firm's cost function is:

C(Q_1, Q₂ )-Q₁ Q₂ +4Q²₁ + 2Q²_2, Where Q₁ is the output of the first product, and Q₂ output of the second product

a) Assume the firm produces the products separately. Calculate the total cost of producing: Q₁ = 10 and Q₂ = 5.

b) Now assume the firm produces both products together. Calculate the total cost of producing: Q₁ = 10 and Q₂ = 5.

c) Does this firm exhibit economies of scope? How do you know?

d) The marginal cost of producing Q₁ is: MC₁ =  -Q₂ + 4Q₁, while the marginal cost of producing Q₂ is: MC₂ = -Q₁ + 6Q₂. Does this firm's production process exhibit cost complementarities? How do you know?