To simplify the expression, we first need to expand the products in the numerator and denominator.

Expanding the products in the numerator:
(2n + 2nc) = 2n + 2nc
(5n + 15) = 5n + 15
(n - 2c) = n - 2c

Expanding the products in the denominator:
(n + 3) = n + 3
(2) = 2
(n^2 - 4c) = n^2 - 4c

Now, substitute the expanded forms back into the expression and simplify:

(2n + 2nc) / (n + 3) (5n + 15) / 2^2 (n - 2c) / (n^2 - 4c)

= (2n + 2nc)(5n + 15)(n - 2c) / (n + 3)(2^2)(n^2 - 4c)

= (2n(5n + 15) + 2nc(5n + 15))(n - 2c) / (n + 3)(4)(n^2 - 4c)

= (10n^2 + 30n + 10cn + 30c)(n - 2c) / (n + 3)(4)(n^2 - 4c)

= (10n^2 + 30n + 10cn + 30c)n - 2(10n^2 + 30n + 10cn + 30c)c / (n + 3)(4)(n^2 - 4c)

= (10n^3 + 30n^2 + 10cn^2 + 30cn - 20cn^2 - 60n - 20c^2n - 60c) / (n + 3)(4)(n^2 - 4c)

= (10n^3 + 30n^2 - 20n^2 + 10cn^2 - 20cn^2 - 60n - 20c^2n - 60c) / (n + 3)(4)(n^2 - 4c)

= (10n^3 + 10cn^2 - 60n - 20c^2n - 60c) / (n + 3)(4)(n^2 - 4c)

The final simplified expression is:
(10n^3 + 10cn^2 - 60n - 20c^2n - 60c) / (n + 3)(4)(n^2 - 4c)