Respuesta :

Distribute the negative sign to the terms inside the parentheses. Such that,
                            3x² - 6x + 7 - x² + 6x - 4
Combining like terms,
                           (3x² - x²) + (-6x + 6x) + (7 - 4)
Simplifying,
                              2x² + 3
The answer is choice 4