问题 解答题
计算:
(1)2
3
+5
12
-2
27

(2)
a2-a
÷
1-
1
a

(3)
412-402

(4)(
b
a
)-(-
a
x
bx
)-(-2ab
x
a
)
(a>0,b>0,y>0).
答案

(1)2

3
+10
3
-6
3
=6
3

(2)

a(a-1)
÷
a-1
a
=
a(a-1)•
a
a-1
=|a|

(3)

412-402
=
(41-40)(41-40)
=9.;

(4)原式=(

b
a
)•(-a)
bx
x2
•(-2ab
x
a
)
=2ab2

单项选择题 A1型题
判断题