第20页

信息发布者:
运算律
使用说明书
B
A
C
2
$-\frac{117}{8}$
解:
$\begin{aligned}&-1 - 1\div3^{2}×\frac{1}{3^{2}}+\vert - 2\vert\\=&-1 - 1\div9×\frac{1}{9}+2\\=&-1-\frac{1}{9}×\frac{1}{9}+2\\=&-1-\frac{1}{81}+2\\=&1-\frac{1}{81}\\=&\frac{80}{81}\end{aligned}$
解:
$\begin{aligned}&\frac{1}{105}\div[\frac{1}{7}-(-\frac{1}{3})-\frac{1}{5}]×(-87)\\=&\frac{1}{105}\div(\frac{1}{7}+\frac{1}{3}-\frac{1}{5})×(-87)\\=&\frac{1}{105}\div(\frac{15 + 35 - 21}{105})×(-87)\\=&\frac{1}{105}\div\frac{29}{105}×(-87)\\=&\frac{1}{105}×\frac{105}{29}×(-87)\\=&\frac{1}{29}×(-87)\\=& - 3\end{aligned}$
解:
$\begin{aligned}&-1^{4}-(1 - 0.5)×\frac{1}{3}×[2-(-3)^{2}]\\=&-1-\frac{1}{2}×\frac{1}{3}×(2 - 9)\\=&-1-\frac{1}{6}×(-7)\\=&-1+\frac{7}{6}\\=&\frac{1}{6}\end{aligned}$
解:
$\begin{aligned}&(-1)^{5}-[-3×(-\frac{2}{3})^{2}-1\frac{1}{3}\div(-2^{2})]\\=&-1-[-3×\frac{4}{9}-\frac{4}{3}\div(-4)]\\=&-1-(-\frac{4}{3}+\frac{1}{3})\\=&-1-(-1)\\=&-1 + 1\\=&0\end{aligned}$