问题 解答题
计算:
(1)-7+13-6+20;
(2)(-49)-(+91)-(-5)+(-9);
(3)1+(-2)+|-2-3|-5;
(4)(-5)×(-7)-5×(-6);
(5)(-
2
3
)÷(-
8
5
)÷(-0.25)

(6)-2•(-
1
2
)2+|-(-2)|3-(-
1
2
)
答案

(1)原式=-7-6+13+20=20;

(2)原式=(-49+5)+(-91-9)=-44-100=-144;

(3)原式=1-2+5-5=-1;

(4)原式=-5×(-7-6)=65;

(5)原式=

2
3
×
5
8
×(-4)=-
5
3

(6)原式=-2×

1
4
+8+
1
2
=-
1
2
+
1
2
+8=8.

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