第34页 - 启东中学作业本七年级数学苏科版宿迁专版

C

a²

$x^{15}$

16

$ \begin{aligned} 解：原式&=-m^5÷m^3 \\ &=-m^2 \\ \end{aligned}$

$ \begin{aligned} 解：原式&=(x-y)^{5-3} \\ &=(x-y)^2 \\ \end{aligned}$

$ \begin{aligned}解：原式&=(-ab)^{5-3} \\ &=(-ab)² \\ &=(ab)² \\ &=a²b² \\ \end{aligned}$

$ \begin{aligned} 解：原式&=(-\frac{1}{2})^{10-3-5} \\ &=(-\frac{1}{2})^2 \\ &=\frac{1}{4} \\ \end{aligned}$

$ \begin{aligned} 原式&=n^3-2n^3 \\ &=-n^3 \\ \end{aligned}$

$ \begin{aligned}解：原式&=2x^3-x^8÷x^5 \\ &=2x^3-x^3 \\ &=x^3 \\ \end{aligned}$

C

B

C