Answer:
Add the numbers that have the same variables and exponents. Hope this helps!
Step-by-step explanation:
-3x³ - 4x - 9
-5x + x - 6x³ - 4 - 5 + 6x³ - 3x³
-6x³ + 6x³ - 3x³ - 5x + x - 4 - 5
