Question

嘎嘎

求第二小題(＞人＜;)

6. 試回答下列兩小題:
(1) 化簡/9+2/20 為a+b 的形式。(其中a,b 為正整數)
x -5x+2
-+1)÷
x²-4
x² +4x+4
x+2
(2) x=19+2720,化簡分式(
7+10=129
(5分)
,並求其值。(4分)
11857

Answer 1

xin

乘法公式

嘎嘎

了解！！謝謝你！

xin

😙

Answer 2

綾

x=2+5^0.5
原式=(x^2-4x+4)/(x+2) + (x^-4)/(x^2+4x+4)
=(x^2-4x+4)/(x+2) + (x+2)(x-2)/(x+2)^2
=(x^2-3x+2)/(x+2)
=(x-2)(x-1)/(x+2)
=(5^0.5)(1+5^0.5)/(4+5^0.5)
=(5+5^0.5)(4-5^0.5)/11
=(15-5^0.5)/11