Answer: - x^2 + 8x - 12
Step-by-step explanation:
The given expression is
(3x^2+2x−9)−(4x^2−6x+3)
The negative sign in front of the second parentheses reverses each sign inside. The expression becomes
3x^2 + 2x− 9 − 4x^2 + 6x - 3
By collecting like terms, it becomes
3x^2 - 4x^2 + 2x + 6x - 9 - 3
- x^2 + 8x - 12