问题
解答题
(1)化简:
(2)解方程:x2+4x-1=0. |
答案
(1)
-18
-9 2
+(
+3 6 3
-2)0+3 (1-
)22
=3
-2 3 2
-2
+1+3+3 2 3
-12
=
-1;3 2 2
(2)x2+4x-1=0,
x2+4x=1,
x2+4x+4=1+4.
(x+2)2=5,
x+2=±
,5
x1=-2+
,x2=-2-5
.5
(1)化简:
(2)解方程:x2+4x-1=0. |
(1)
-18
-9 2
+(
+3 6 3
-2)0+3 (1-
)22
=3
-2 3 2
-2
+1+3+3 2 3
-12
=
-1;3 2 2
(2)x2+4x-1=0,
x2+4x=1,
x2+4x+4=1+4.
(x+2)2=5,
x+2=±
,5
x1=-2+
,x2=-2-5
.5