Answer:
- 12x² + 9x + 9
Step-by-step explanation:
(- 10x² + 2) + (- 2x² + 9x + 7 ) ← remove parenthesis
= - 10x² + 2 - 2x² + 9x + 7 ← collect like terms
= - 12x² + 9x + 9
