(1)计算:?2?2+3(tan60°)?1?(1?3)2?(π?3.14)0;(2)先化简,再选择一个合适的x值代入

2025-01-04 07:42:13
推荐回答(1个)
回答1:

(1)原式=?

1
4
+3?(
3
)?1+1?
3
?1(4分)
=?
1
4
+
3
+1?
3
?1
(6分)
=?
1
4
(8分);
(2)原式=
x+x+1
x+1
÷
1?x2?3x2
1?x2
-
1
x?1
(2分)
=
2x+1
x+1
÷
(1+2x)(1?2x)
(x+1)(1?x)
-
1
x?1

2x+1
x+1
×
(1+x)(1?x)
(2x+1)(1?2x)
-
1
x?1

=
1?x
1?2x
-
1
x?1

=
?x2+4x?2
(1?2x)(x?1)
.(6分)
取x