试题

题目:
计算:
(1)-8+10+2+(-1)
(2)(
1
4
-
1
6
+
1
9
)×(-36)

(3)-5×(-6)+3×(-8)-(-4)×(-7)
(4)-32×(-2)+42÷(-2)3
(5)-12+|-8|÷(3-5)-(-2)3
答案
解:(1)原式=-8+10+2-1     
=〔(-8)+(-1)(10+2)〕
=(-9)+12
=3;              

(2)原式=
1
4
×(-36)-
1
6
×(-36)+
1
9
×(-36)
=(-9)+6+(-4)
=〔(-9)+(-4)〕+6
=(-13)+6
=-7;               

(3)原式=30+(-24)-(+28)
=30-24-28               
=-22;
             
(4)原式=-9×(-2)+16÷(-8)
=18+(-2)
=18-2                  
=16;
                   
(5)原式=-1+8÷(-2)-(-8)
=-1+(-4)-(-8)
=-1-4+8           
=3.
解:(1)原式=-8+10+2-1     
=〔(-8)+(-1)(10+2)〕
=(-9)+12
=3;              

(2)原式=
1
4
×(-36)-
1
6
×(-36)+
1
9
×(-36)
=(-9)+6+(-4)
=〔(-9)+(-4)〕+6
=(-13)+6
=-7;               

(3)原式=30+(-24)-(+28)
=30-24-28               
=-22;
             
(4)原式=-9×(-2)+16÷(-8)
=18+(-2)
=18-2                  
=16;
                   
(5)原式=-1+8÷(-2)-(-8)
=-1+(-4)-(-8)
=-1-4+8           
=3.
考点梳理
有理数的混合运算.
(1)先去括号,在进行有理数的加减计算就可以了;
(2)利用乘法分配律直接去括号的就可以;
(3)先计算乘法,再计算加减就可以得出结果;
(4)先计算乘方,再计算乘法最后计算加减就可以求出结果;
(5)先计算乘方和去绝对值,再计算除法,最后计算加减就可以了.
本题考查了去绝对值的运用,乘法分配律的运用,有理数的乘法运算乘除运算及有理数的加减运算的运用.
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