问题:
(1)3y 2-6xy
(2)25x 2-16y 2
(3)3a 2-6a+3
(4)x 2(a-b) 2-y 2(b-a) 2.
(1)3y 2-6xy
(2)25x 2-16y 2
(3)3a 2-6a+3
(4)x 2(a-b) 2-y 2(b-a) 2.
(2)25x 2-16y 2
(3)3a 2-6a+3
(4)x 2(a-b) 2-y 2(b-a) 2.
参考答案: