Answer:
1. 9x
2. 9x
3. 6n² + n + 6
4. 3x² - x + 4
5. 6x² + 2x + 6
Step-by-step explanation:
1. 4x + 5x = 9x
2. (4x + 5x) + [4y - (-5y)] = 9x + 9y
3. (6n² + 4n - 2) + (-3n + 8)
= 6n² + 4n - 3n - 2 + 8
= 6n² + n + 6
4. (2x² + 4) + (x²-x) = 2x² + x² - x + 4
= 3x² - x + 4
5. (x² + x - 2) + (5x² + x + 8)
= x² + 5x² + x + x - 2 + 8
= 6x² + 2x + 6
To add polynomials, arrange the them first then combine/add those with similar terms.
