A 4b 3a 2b 2 6ab 3 July 8, 2019 16 32 64 128 6) (2a + 3b) ^ 2 - 4a(a - 6b) (3a ^ 2 + 3ab + 3b ^ 2)/(4a + 4b) * (2a ^ 2 - 2b ^ 2)/(9a ^ 3 - 9b ^ 3)