a与a/3b²通分.还有a－b,b/a－b,1/a²－b²突然忘了.

a与a/3b²通分.还有a－b,b/a－b,1/a²－b²突然忘了.
a与a/3b²通分.还有a－b,b/a－b,1/a²－b²
突然忘了.

a与a/3b²通分.还有a－b,b/a－b,1/a²－b²突然忘了.
3ab^2/3b^2,
a/3b^2.
(a十b)(a一b)^2/(a^一b^2),
b(a十b)/(a^2一b^2),
1/(a^2一b^2)