Answer:
The answer to your question is a² + 9a + 20
Step-by-step explanation:
10a² + 3a + 25 - (9a² - 6a + 5)
- Remove parentheses changing the sign of the second polynomial
10a² + 3a + 25 - 9a² + 6a - 5
- Group like terms
(10a² - 9a²) + (3a + 6a) + (25 - 5)
- Simplify and result
a² + 9a + 20