第83页 - 经纶学典学霸八年级数学上下册【江苏国标】

D

A

C

$\frac{1}{(x+1)^{2}}和\frac{1}{2(x+1)}$

$30a^{3}bc$

$4x^{2}(m-n)$

$m(m^{2}+n^{2})(n^{2}-m^{2})$

$解:\frac{x+2}{(x-2)^{2}(x+2)}$

$\frac{x(x-2)}{(x-2)^{2}(x+2)}$

$解:\frac{y(x-y)}{x(x-y)^{3}}$

$-\frac{x^{2}}{x(x-y)^{3}}$

$解:\frac{2(x+1)(x+3)(x-3)}{2×(x+3)(x-3)}$

$\frac{x^{2}(x-3)}{2x(x+3)(x-3)}$

$\frac{2x(x-1)}{2x(x+3)(x-3)}$

$\ 解:\frac{x+1}{x(x+1)^{2}}$

$-\frac{x}{x(x+1)^{2}}$

B

A

$\frac{2}{3} $

3

5或10

$解:\frac{12c}{8ab^{2}c^{2}},-\frac{a^{2}b}{8ab^{2}c^{2}}$

$解:\frac{3yz}{6x^{2}y^{2}z}$

$\frac{5x}{6x^{2}y^{2}z}$

$\frac{8cxyz}{6x^{2}y^{2}z}$