(9x² + 3x +5) + (x² + 5x + 8)

(x² + 8) - (x +1)

(6x³ + 2x² + 6x + 3) - (3x² -6x -6)

(5x - 4x² + 8x + 9) + (8x + 6 - x²)

(8x⁴ - 5x - 5x² + 8) - (9x⁴ + 7x³ - 7x² +8) + (2x³ - 7x² + 2x - 5)

-(2x² - 7x +5) - (x² + 2x + 1)