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電子課本網(wǎng) 第122頁

第122頁

信息發(fā)布者:
C
B
B
B
C
$解:原式?=\frac 4{36x^2}+\frac {30x}{36x^2}-\frac {27}{36x^2}?$
$? =\frac {30x-23}{36x^2}?$
解:原式?$=\frac {2x-2y}{x-y}$?
?$ =2$?
解:原式?$=\frac {x^2-(x-y)(x+y)}{x+y}$?
?$ =\frac {x^2-x^2+y^2}{x+y}$?
?$ =\frac {y^2}{x+y}$?
解:原式?$=\frac {(x+2y)(x-2y)}{(x+y)^2}×\frac {x(x+y)}{x+2y}$?
?$=\frac {x(x-2y)}{x+y}$?