问题
解答题
(1)解方程:x2-4x-4=0; (2)计算:(2
|
答案
(1)∵x2-4x=4,
∴x2-4x+4=4+4,
∴(x-2)2=8,
∴x-2=±22
解得x1=2+2
,x2=2-22
.2
(2)(2
-24
)÷18
+23 3 2
=(4
-36
)÷2
+3 6
=4
-2
+6 6
=4
.2
(1)解方程:x2-4x-4=0; (2)计算:(2
|
(1)∵x2-4x=4,
∴x2-4x+4=4+4,
∴(x-2)2=8,
∴x-2=±22
解得x1=2+2
,x2=2-22
.2
(2)(2
-24
)÷18
+23 3 2
=(4
-36
)÷2
+3 6
=4
-2
+6 6
=4
.2