Question

先化简，再把x取一个你最喜欢的数代入求值：（x²-4/x²-4x+4 + 2-x/x+2）÷x/x-2

Answer 1

原式=[(x+2)(x-2)/(x-2)²-(x-2)/(x+2)]×(x-2)/x
=[(x+2)/(x-2)-(x-2)/(x+2)]×(x-2)/x
=[(x+2)²-(x-2)²]/(x+2)(x-2)×(x-2)/x
=8x/(x+2)(x-2) ×(x-2)/x
=8/(x+2)
当x=-1时
原式=8/(-1+2)=8

Answer 2

原式=[(x+2)(x-2)/(x-2)²+(2-x)/(x+2)]*(x-2)/x
=[(x+2)/(x-2)+(2-x)/(x+2)]*(x-2)/x
=[(x+2)²-(x-2)²]/(x+2)(x-2)*(x-2)/x
=(x²+4x+4-x²+4x-4)/(x+2)(x-2)*(x-2)/x
=8x/(x+2)(x-2)*(x-2)/x
=8/(x+2)
令x=6
原式=8/(6+2)=1

Answer 3

0123456789；；；就好好干

Answer 4

真心不知道哪些是分子，哪些是分母~

Answer 5