Answer:
5x^2 + 4x + 3.
Step-by-step explanation:
While I'm a little confused on what is closed and open parenthesis/brackets, I think I understand what you mean. In (5x^2+3x-2)+(3x-2x+5), the brackets can simply be removed as there is no multiplication between them. This means we get 5x^2 + 3x - 2 + 3x - 2x + 5. Combining like variables, we get 5x^2 + 4x + 3.
