题目内容
(1)计算:(-2)2+20110-2cos60°
(2)计算:(
-
)÷
(3)解方程:2x2-1=3x.
(2)计算:(
x2 |
x-1 |
2x |
1-x |
x |
x-1 |
(3)解方程:2x2-1=3x.
(1)原式=4+1-2×
=4;
(2)原式=(
+
)•
=
•
=x+2;
(3)2x2-1=3x,
整理得:2x2-3x-1=0,
这里a=2,b=-3,c=-1,
∵△=b2-4ac=9+8=17,
∴x=
,
则x1=
,x2=
.
1 |
2 |
=4;
(2)原式=(
x2 |
x-1 |
2x |
x-1 |
x-1 |
x |
=
x(x+2) |
x-1 |
x-1 |
x |
=x+2;
(3)2x2-1=3x,
整理得:2x2-3x-1=0,
这里a=2,b=-3,c=-1,
∵△=b2-4ac=9+8=17,
∴x=
3±
| ||
4 |
则x1=
3+
| ||
4 |
3-
| ||
4 |
练习册系列答案
相关题目