问题
解答题
先化简,后求值:(
|
答案
(
3x |
x-1 |
x |
x+1 |
x2-1 |
x |
=
3x(x+1)-x(x-1) |
x2-1 |
x2-1 |
x |
=
x(2x+4) |
x2-1 |
x2-1 |
x |
=2x+4;
当x=-2时,原式=2x+4=0.
先化简,后求值:(
|
(
3x |
x-1 |
x |
x+1 |
x2-1 |
x |
=
3x(x+1)-x(x-1) |
x2-1 |
x2-1 |
x |
=
x(2x+4) |
x2-1 |
x2-1 |
x |
=2x+4;
当x=-2时,原式=2x+4=0.