6a/9a^2-1 + 3a+1/3-9a + 3a-1/6a+2
6a/(3a-1)•(3a+1) + 3a+1/-(9a-3) + 3a-1/2(3a+1)
6a/(3a-1)•(3a+1) + 3a+1/-3(3a-1) + 3a-1/2(3a+1)
6a/(3a-1)•(3a+1) + 3a+1/3(3a-1) + 3a-1/2(3a+1)
36a-2(3a+1)•(3a+1)+3(3a-1)•(3a-1)/6(3a-1)•(3a+1)
36a-2(3a+1)^2+3(3a-1)^2/6(3a-1)•(3a+1)
36a-2(9a^2+6a+1)+3(9a^2-6a+1)/6(3a-1)•(3a+1)
36a-18a^2-12a-2+27a^2-18a+3/6(3a-1)•(3a+1)
6a+9a^2+1/6(3a-1)•(3a+1)
9a^2+6a+1/6(3a-1)•(3a+1)
(3a+1)^2/6(3a-1)•(3a+1)
3a+1/6(3a-1)
Ответ: 3a+1/6(3a-1)