Answer:
D
Step-by-step explanation:
Distribute the parenthesis and collect like terms.
Note the second parenthesis is distributed by - 1
5x³ + 4x² - 6x² + 2x + 9 ← collect like terms
= 5x³ - 2x² + 2x + 9
1.3^3-0.2t^2-6t-8
