Question

化簡：(a-

a

a+1

)÷

a2-2a

a2-4

×

1

a+2

Answer 1

分析：首先把括號里的式子進(jìn)行通分，然后把除法運(yùn)算轉(zhuǎn)化成乘法運(yùn)算，最后進(jìn)行約分化簡．

解答：解：(a-

a

a+1

)÷

a2-2a

a2-4

×

1

a+2

=(a-

a

a+1

)×

(a+2)(a-2)

a(a-2)

×

1

a+2

=(a-

a

a+1

)×

1

a

=a×

1

a

-

a

a+1

×

1

a

=1-

1

a+1

=

a

a+1

．

點(diǎn)評：分式的四則運(yùn)算是整式四則運(yùn)算的進(jìn)一步發(fā)展，在計算時，首先要弄清楚運(yùn)算順序，先去括號，再進(jìn)行分式的乘除．