问题
解答题
计算:
|
答案
-x x2-4 1 2x-4
=
-x (x+2)(x-2) 1 2(x-2)
=
-2x 2(x-2)(x+2)
(2分)x+2 2(x-2)(x+2)
=
(4分)x-2 2(x+2)(x-2)
=
(或1 2(x+2)
)(5分)1 2x+4
计算:
|
-x x2-4 1 2x-4
=
-x (x+2)(x-2) 1 2(x-2)
=
-2x 2(x-2)(x+2)
(2分)x+2 2(x-2)(x+2)
=
(4分)x-2 2(x+2)(x-2)
=
(或1 2(x+2)
)(5分)1 2x+4