Answer:
Step-by-step explanation:
Like terms have same variable with same power. Combine the like terms. Add / subtract the coeffiecient of the like terms.
9x² and 9x² are like terms
-8 and 3 are like terms.
9x² - 8 + 9x² + 9x + 3 = 9x² + 9x² +9x - 8 + 3
= 18x² + 9x - 5
