问题
解答题
(1)化简:
(2)解方程:x2+4x-1=0. |
答案
(1)
18 |
|
| ||||
|
3 |
(1-
|
=3
2 |
3 |
2 |
2 |
3+3
| ||
3 |
2 |
=
3
| ||
2 |
(2)x2+4x-1=0,
x2+4x=1,
x2+4x+4=1+4.
(x+2)2=5,
x+2=±
5 |
x1=-2+
5 |
5 |
(1)化简:
(2)解方程:x2+4x-1=0. |
(1)
18 |
|
| ||||
|
3 |
(1-
|
=3
2 |
3 |
2 |
2 |
3+3
| ||
3 |
2 |
=
3
| ||
2 |
(2)x2+4x-1=0,
x2+4x=1,
x2+4x+4=1+4.
(x+2)2=5,
x+2=±
5 |
x1=-2+
5 |
5 |