1. 计算:$-1-(1-0.5)×\frac{1}{3}×[2-(-3)^2].$
答案
1. 【解】原式$=-1-\frac{1}{2}×\frac{1}{3}×(2-9)=-1-\frac{1}{2}×\frac{1}{3}×(-7)=-1-(-\frac{7}{6})=-1+\frac{7}{6}=\frac{1}{6}.$
2. 计算:$-2^2 ÷ \dfrac{4}{3} - [2^2 - (1 - \dfrac{1}{2} × \dfrac{1}{3})] × 12.$
答案
2. 【解】原式$=-4×\frac{3}{4}-[4-(1-\frac{1}{6})]×12=-3-(4-\frac{5}{6})×12=-3-4×12+\frac{5}{6}×12=-3-48+10=-41.$
3. 计算:$|-4| × (-3) - [ 3.45 + ( 1\dfrac{1}{4} - 2 ) ÷ \dfrac{1}{8} ].$
答案
3. 【解】原式$=-12-(3.45-\frac{3}{4}×8)$
$=-12-(3.45-6)$
$=-12+2.55$
$=-9.45.$
$=-12-(3.45-6)$
$=-12+2.55$
$=-9.45.$
4.计算:$-(-3)^3 + (-2)^5 ÷ [(-3) - (-7)]$
答案
4. 【解】原式$=-(-27)+(-32)÷4=27-32÷4$
$=27-8=19.$
$=27-8=19.$
5. 计算:$-3^2 - (-2 - 5)^2 - \left| -\dfrac{1}{4} \right| × (-2)^4$
答案
5. 【解】原式$=-9-(-7)^2-\frac{1}{4}×16=-9-49-4=-62.$
6.计算:$\frac{5}{31} × (-\frac{2}{9}) × (-2\frac{1}{15}) × (-4\frac{1}{2})$
答案
6. 【解】原式$=-\frac{5}{31}×\frac{2}{9}×\frac{31}{15}×\frac{9}{2}$
$=-(\frac{5}{31}×\frac{31}{15})×(\frac{2}{9}×\frac{9}{2})$
$=-\frac{1}{3}×1$
$=-\frac{1}{3}.$
$=-(\frac{5}{31}×\frac{31}{15})×(\frac{2}{9}×\frac{9}{2})$
$=-\frac{1}{3}×1$
$=-\frac{1}{3}.$
7.计算: $( \dfrac{1}{2} - \dfrac{1}{3} - \dfrac{1}{12} ) × (-12)$
答案
7. 【解】$(\frac{1}{2}-\frac{1}{3}-\frac{1}{12})×(-12)$
$=-12×\frac{1}{2}+12×\frac{1}{3}+12×\frac{1}{12}$
$=-6+4+1$
$=-1.$
$=-12×\frac{1}{2}+12×\frac{1}{3}+12×\frac{1}{12}$
$=-6+4+1$
$=-1.$
8. 计算:$-11×\frac{2}{3} - 0.35×\frac{2}{7} + \frac{1}{3}×(-11) - \frac{5}{7}×0.35.$
答案
8. 【解】$-11×\frac{2}{3}-0.35×\frac{2}{7}+\frac{1}{3}×(-11)-\frac{5}{7}×0.35$
$=-11×\frac{2}{3}-11×\frac{1}{3}-0.35×\frac{2}{7}-0.35×\frac{5}{7}$
$=-11×(\frac{2}{3}+\frac{1}{3})-0.35×(\frac{2}{7}+\frac{5}{7})$
$=-11-0.35$
$=-11.35.$
$=-11×\frac{2}{3}-11×\frac{1}{3}-0.35×\frac{2}{7}-0.35×\frac{5}{7}$
$=-11×(\frac{2}{3}+\frac{1}{3})-0.35×(\frac{2}{7}+\frac{5}{7})$
$=-11-0.35$
$=-11.35.$
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