(1)最简公分母是18a2b2c,
=x 6ab2
=x×3ac 6ab2×3ac
,3acx 18a2b2c
=y 9a2bc
=y×2b 9a2bc×2b
;2by 18a2b2c
(2)最简公分母是(a+1)2(a-1),
=a?1
a2+2a+1
=(a?1)×(a?1)
(a+1)2×(a?1)
,
a2?2a+1
(a+1)2(a?1)
=6
a2?1
=6×(a+1) (a+1)(a?1)×(a+1)
.6a+6 (a+1)2(a?1)