(x?1)(x+1) |
(x+1)2 |
x+1 |
x?1 |
=
x?1 |
x+1 |
x+1 |
x?1 |
=
(x?1)2?(x+1)2 |
(x?1)(x+1) |
=
?4x |
x2?1 |
把x=0代入,得:原式=0;
或把x=2代入,得:原式=
?4×2 |
22?1 |
8 |
3 |
或把x=-2代入,得:原式=
?4×(?2) |
(?2)2?1 |
8 |
3 |
x2?1 |
x2+2x+1 |
x+1 |
x?1 |
(x?1)(x+1) |
(x+1)2 |
x+1 |
x?1 |
x?1 |
x+1 |
x+1 |
x?1 |
(x?1)2?(x+1)2 |
(x?1)(x+1) |
?4x |
x2?1 |
?4×2 |
22?1 |
8 |
3 |
?4×(?2) |
(?2)2?1 |
8 |
3 |