Answer :
when u got a + in the middle, parenthesis are not needed
3x^2 - 2 + 2x^2 - 6x + 3...now we combine like terms
5x^2 - 6x + 1 <==
3x^2 - 2 + 2x^2 - 6x + 3...now we combine like terms
5x^2 - 6x + 1 <==