问题 解答题
计算或求
(1)5x2-
1
5
=0
(2)64(x-1)3+125=0
(3)
(-
1
5
)2
+
3-8
-
1-(
4
5
)2
答案

(1)5x2-

1
5
=0

5x2=

1
5

x2=

1
25

x=±

1
5

(2)64 (x-1)3+125=0

64 (x-1)3=-125

(x-1)3=-

125
64

x-1=-

3
125
64

x-1=-

5
4

x=1-

5
4

x=-

1
4

(3)原式=

1
5
-2-
25
25
-
16
25

=

1
5
-2-
9
25

=

1
5
-2-
3
5

=-2

2
5

不定项选择
选择题