We are asked to perform the following addition of trinomials:
(3x^2 - 10x + 6) + ( - 2x^2 + 8x - 3)
so we proceed to remove parentheses noticing that since neither parenthesis is preceded by a negative sign, we don't have to flip signs in the terms of the trinomials. The removal is then straight forward:
3 x^2 - 10 x + 6 - 2 x^2 + 8 x - 3
and now we combine like terms:
3 x^2 - 2 x^2 = x^2
- 10 x + 8 x = - 2 x
6 - 3 = 3
Therefore after combining we end up with:
x^2 - 2 x + 3