问题
解答题
计算: (1)
(2)
(3)(2ab2c-3)-2÷(a-2b)3 (4)
(5)
|
答案
(1)原式=
x2 |
x-1 |
x+1 |
1 |
=
x2 |
x-1 |
(x+1)(x-1) |
x-1 |
=
x2-(x2-1) |
x-1 |
=
1 |
x-1 |
(2)原式=2+1+3+2=8;
(3)原式(2ab2c-3)-2•(a-2b)-3
=
1 |
4 |
=
1 |
4 |
=
a4c6 |
4b7 |
(4)原式=
(x+y)(x-y) |
x |
x2-2xy+y2 |
x |
=
(x+y)(x-y) |
x |
x |
(x-y)2 |
=
x+y |
x-y |
(5)原式=
6 |
(x+3)(x-3) |
x-3 |
(x+3)(x-3) |
=
x+3 |
(x+3)(x-3) |
=
1 |
x-3 |