Question

計(jì)算：(

x+2

x2-2x

-

x-1

x2-4x+4

)÷

x-4

x

(2-x)2．

Answer 1

分析：此題可以首先把除法變?yōu)槌朔ǎ�再進(jìn)一步運(yùn)用乘法分配律把括號(hào)外的分配進(jìn)去，最后通分相加減．

解答：解：原式=[

x+2

x(x-2)

-

x-1

(x-2)2

]•

x

x-4

（x-2）²
=

(x+2)(x-2)

x-4

-

x(x-1)

x-4

=

x-4

x-4

=1．

點(diǎn)評(píng)：本題主要考查分式的混合運(yùn)算，通分、因式分解和約分是解答的關(guān)鍵．