Answer:
The expressions are -x² - 9x - 9.
Step-by-step explanation:
First, you have to expand the expressions :
[tex] - 2(4 {x}^{2} + 6) + (7 {x}^{2} - 9x + 3)[/tex]
[tex] = - 8 {x}^{2} - 12 + 7 {x}^{2} - 9x + 3[/tex]
Next, you have to collect like terms :
[tex] - 8 {x}^{2} + 7 {x}^{2} - 9x - 12 + 3[/tex]
[tex] = - {x}^{2} - 9x - 9[/tex]
