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> (1)计算:8-(5-1)0+2sin45°(2)解方程:x2+4x=5.-数学
(1)计算:8-(5-1)0+2sin45°(2)解方程:x2+4x=5.-数学
题目简介
(1)计算:8-(5-1)0+2sin45°(2)解方程:x2+4x=5.-数学
题目详情
(1)计算:
8
-(
5
-1
)
0
+2sin45°
(2)解方程:x
2
+4x=5.
题型:解答题
难度:中档
来源:不详
答案
(1)原式=2
2
-1+
2
=
2
-1;
(2)由原方程,得
x2+4x+22=5+22,
配方,得
(x+2)2=9,
开方,得
x+2=±3,
解得,x1=1,x2=-5.
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题目简介
(1)计算:8-(5-1)0+2sin45°(2)解方程:x2+4x=5.-数学
题目详情
(2)解方程:x2+4x=5.
答案
(2)由原方程,得
x2+4x+22=5+22,
配方,得
(x+2)2=9,
开方,得
x+2=±3,
解得,x1=1,x2=-5.