Answer:
D. 8x²y² - 15x²y + xy² + 5y
General Formulas and Concepts:
Pre-Algebra
Algebra I
Explanation:
Step 1: Define Expression
(8x²y² - 9x²y + 9y) - (6x²y - xy² + 4y)
Step 2: Simplify
- Distribute negative: 8x²y² - 9x²y + 9y - 6x²y + xy² - 4y
- Combine like terms (x²y): 8x²y² - 15x²y + 9y + xy² - 4y
- Combine like terms (y): 8x²y² - 15x²y + xy² + 5y