登录
6. 已知 $ a＜0 $，$ b＞0 $，$ |a|＜|b|＜1 $，则下列判断正确的是(
A.$ a＜1-b＜-b＜1+a $
B.$ -b＜1+a＜a＜1-b $
C.$ a＜1+a＜-b＜1-b $
D.$ -b＜a＜1-b＜1+a $
D
)A.$ a＜1-b＜-b＜1+a $
B.$ -b＜1+a＜a＜1-b $
C.$ a＜1+a＜-b＜1-b $
D.$ -b＜a＜1-b＜1+a $
答案
6.D
7. 小薇的体重是45.85 kg，用四舍五入法将45.85精确到0.1的近似值为
45.9
.答案
7.45.9
8.若$|a-1|$与$|b+2|$互为相反数，则$(a+b)^{100}$的值为
1
.答案
8.1
9. 已知a，b互为相反数，m，n互为倒数，则$3(a+b)-2019mn$的值为
-2 019
。答案
9.-2 019
10. 用计算器计算 $19^5$ 的过程为：输入
① ⑨ xⁿ ⑤ =（答案不唯一）
，结果是2 476 099
。答案
10.① ⑨ xⁿ ⑤ =（答案不唯一） 2 476 099
三、解答题
11. 计算:
(1) $-8+(-6)+22-5$;
(2) $(-3)^2 × (-\frac{2}{3}+\frac{5}{9})$;
(3) $(-5)+(-7)-(+13)-(-19)$;
(4) $999\frac{4}{5} × (-5)$;
(5) $-1^{2018}-\frac{1}{3} × [ (-5) × (-\frac{3}{5})^2 +0.8 ]$;
(6) $5 ÷ [ (-1)^3 -4 ] +3^2 × (-1)$;
(7) $( \frac{1}{2}-\frac{5}{8}-\frac{3}{4} ) × (-24)$;
(8) $(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5$;
(9) $(-5) ×6 × (-\frac{4}{5}) ÷ (-4)$;
(10) $-1+2\frac{2}{3}-6.5-\frac{2}{3}$;
(11) $-1^4 - |0.5-1| ÷3 × [2-(-3)^2]$;
(12) $-7+(-8)-(-18)-13$;
(13) $(-1)^3 × (-5)-(-3) ÷ (-\frac{1}{4})$;
(14) $( \frac{2}{9}-\frac{1}{4}-\frac{1}{18} ) ÷ (-\frac{1}{36})$;
(15) $-1^{2000}-2\frac{1}{4} × [13-(-5)^2]$;
(16) $(2\frac{1}{3}-3\frac{1}{2}+1\frac{4}{45}) ÷ (-1\frac{1}{6})$;
(17) $-6 - |-0.6| + (-5) + \frac{3}{5}$;
(18) $5 ÷ [ \frac{1}{2} - (-1+\frac{2}{3}) ] × \frac{6}{5} + [ (-2)^2 ÷5 ]$.
11. 计算:
(1) $-8+(-6)+22-5$;
(2) $(-3)^2 × (-\frac{2}{3}+\frac{5}{9})$;
(3) $(-5)+(-7)-(+13)-(-19)$;
(4) $999\frac{4}{5} × (-5)$;
(5) $-1^{2018}-\frac{1}{3} × [ (-5) × (-\frac{3}{5})^2 +0.8 ]$;
(6) $5 ÷ [ (-1)^3 -4 ] +3^2 × (-1)$;
(7) $( \frac{1}{2}-\frac{5}{8}-\frac{3}{4} ) × (-24)$;
(8) $(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5$;
(9) $(-5) ×6 × (-\frac{4}{5}) ÷ (-4)$;
(10) $-1+2\frac{2}{3}-6.5-\frac{2}{3}$;
(11) $-1^4 - |0.5-1| ÷3 × [2-(-3)^2]$;
(12) $-7+(-8)-(-18)-13$;
(13) $(-1)^3 × (-5)-(-3) ÷ (-\frac{1}{4})$;
(14) $( \frac{2}{9}-\frac{1}{4}-\frac{1}{18} ) ÷ (-\frac{1}{36})$;
(15) $-1^{2000}-2\frac{1}{4} × [13-(-5)^2]$;
(16) $(2\frac{1}{3}-3\frac{1}{2}+1\frac{4}{45}) ÷ (-1\frac{1}{6})$;
(17) $-6 - |-0.6| + (-5) + \frac{3}{5}$;
(18) $5 ÷ [ \frac{1}{2} - (-1+\frac{2}{3}) ] × \frac{6}{5} + [ (-2)^2 ÷5 ]$.
答案
(1)3
(2)-1
(3)-6
(4)-4 999
(5)$-\frac{2}{3}$
(6)-10
(7)21
(8)1.9
(9)-6
(10)-5.5
(11)$\frac{1}{6}$
(12)-10
(13)-7
(14)3
(15)26
(16)$\frac{1}{15}$
(17)-11
(18)8
(2)-1
(3)-6
(4)-4 999
(5)$-\frac{2}{3}$
(6)-10
(7)21
(8)1.9
(9)-6
(10)-5.5
(11)$\frac{1}{6}$
(12)-10
(13)-7
(14)3
(15)26
(16)$\frac{1}{15}$
(17)-11
(18)8
