计算:(1)(-12)+(-23)+(-56);(2)(-12)+314+2.75+(-612)(3)(-1)+(+2)+(-3)+(+4)+…(-2001)+(+2002)+(-2003)+(+2004)(4)-14-(1-0.5)×13×〔2-(-3)2〕(5)25×34-(-25)×12+25×14(6)-数学

题文

计算:
(1)(-
1
2
)+(-
2
3
)+(-
5
6
);      
(2)(-
1
2
)+3
1
4
+2.75+(-6
1
2

(3)(-1)+(+2)+(-3)+(+4)+…(-2001)+(+2002)+(-2003)+(+2004)
(4)-14-(1-0.5)×
1
3
×〔2-(-3)2
(5)25×
3
4
-(-25)×
1
2
+25×
1
4

(6)-|-32|÷3×(-
1
3
)-(-2)3
题型:解答题  难度:中档

答案

(1)原式=-(
1
2
+
2
3
+
5
6
)=-2;
(2)原式=(-
1
2
-6
1
2
)+(3.25+2.75)=-7+6=-1;
(3)原式=(-1+2)+(-3+4)+…+(-2003+2004)=1+1+…+1=1002;
(4)原式=-1-
1
2
×
1
3
×(-7)=-1+
7
6
=
1
6

(5)原式=25×(
3
4
+
1
2
+
1
4
)=25×
3
2
=
75
2

(6)原式=-9×
1
3
×(-
1
3
)+8=1+8=9.