a) 9a-(4+ a)(2a + 1) = 9a - (8a+ 4+2a² + a) = 9a-9a-4-2a² = -2a²-4 6) 3a³+ (2a+3a²) (6-a) = 3a³ + 12a-2a² + 18a²3a³ = 16a² + 12a B) (3-x)(1+2x) + (1-x)(3-2x) = 3 +6x-x-2x²+3-2x-3x + 2x² = 6 r) (x-2)(2x-6)(x-3)(2x-4)=2x² - 6x-4x+12-(2x² - 4x-6x + 12) = 2x² - 10x + 12-2x² + 10x - 12 = 0
a) 9a-(4+ a)(2a + 1) = 9a - (8a+ 4+2a² + a) = 9a-9a-4-2a² = -2a²-4 6) 3a³+ (2a+3a²) (6-a) = 3a³ + 12a-2a² + 18a²3a³ = 16a² + 12a B) (3-x)(1+2x) + (1-x)(3-2x) = 3 +6x-x-2x²+3-2x-3x + 2x² = 6 r) (x-2)(2x-6)(x-3)(2x-4)=2x² - 6x-4x+12-(2x² - 4x-6x + 12) = 2x² - 10x + 12-2x² + 10x - 12 = 0