第26页 - 亮点给力提优课时作业本七年级数学江苏版

A

C

B

8

$-10$

$－5.5$

$-1$

3

$ \begin{aligned}解：原式&=-1\frac{2}{3}+2\frac{1}{2} \\ &=2\frac{1}{2}-1\frac{2}{3} \\ &=\frac{5}{6} \\ \end{aligned}$

$ \begin{aligned} 解：原式&=5\frac{5}{6}+(-8\frac{2}{3}) \\ &=-(8\frac{2}{3}-5\frac{5}{6}) \\ &= -2\frac{5}{6} \\ \end{aligned}$

$ \begin{aligned} 解：原式&=－\frac{2}{3}－\frac{1}{12} \\ &=-(\frac{2}{3}+\frac{1}{12}) \\ &=－\frac{3}{4} \\ \end{aligned}$

A

C