亚洲激情+欧美激情,无码任你躁久久久久久,我的极品美女老婆,性欧美牲交在线视频,亚洲av高清在线一区二区三区

電子課本網(wǎng) 第118頁(yè)

第118頁(yè)

信息發(fā)布者:
④⑤
0
$\frac{3x}{x-4}$
$\frac {x+2y}{x-2y}$
$\frac{2}{5}$
$解:\frac{1}{3x^{2}}=\frac {4y}{12x^{2}y}$
$\frac{5}{12xy}=\frac{5x}{12x^{2}y}\ $
$解:\frac {x}{x-y}=\frac {x(x+y)^{2}}{(x-y)(x+y)^{2}}$
$\frac {y}{x^{2}+2xy+y^{2}}=\frac {y(x-y)}{(x-y)(x+y)^{2}}$
$\frac {2}{y^{2}-x^{2}}=-\frac {2(x+y)}{(x-y)(x+y)^{2}}$
$解:\frac {x}{x^{2}-1}=\frac {x(x-1)}{(x-1)^{2}(x+1)}$
$\frac {2}{x^{2}-2x+1}=\frac {2(x+1)}{(x-1)^{2}(x+1)}$
$解:原式=\frac {x}{3x-y}$
$當(dāng)x=\frac{4}{3},y=-\frac{2}{3}時(shí),原式=\frac{2}{7}$
C
$解:\frac{m^{2}+3}{m+1}=\frac{m^{2}-1+4}{m+1}=\frac{m^{2}-1}{m+1}+\frac{4}{m+1}=m-1+\frac{4}{m+1}$

5
$解:\frac {1}{x-1}=\frac {x(x+1)}{x(x+1)(x-1)}$
$\frac {1}{x^{2}-1}=\frac {x}{x(x+1)(x-1)}$
$\frac {1}{x^{2}+x}=\frac {x-1}{x(x+1)(x-1)}$