Question

初中数学计算题（过程）

(1)化简分式(x^2-1/x^2+2x+1)-(x+1/x-1)
(2)解方程(x-1/x)-(x/x-1)=5/2
(3)解不等式组2-x>0
( 5x+1/2)+1>=(2x-1/3)

Answer 1

(1)化简分式(x^2-1/x^2+2x+1)-(x+1/x-1)
=(x+1)(x-1)/(x+1)^2-(x+1)/(x-1)
=(x-1)/(x+1)-(x+1)/(x-1)
=[(x-1)^2-(x+1)^2]/(x^2-1)
=-4x/(x^2-1)
(2)解方程(x-1/x)-(x/x-1)=5/2
(-2x+1)/x(x-1)=5/2
-4x+2=5x^2-5x
5x^2-x-2=0
(x-1/10)^2=41/100
x=(1±√41)/10

(3)解不等式组2-x>0
( 5x+1/2)+1>=(2x-1/3)
x<2
5x+3/2>=2x-1/3
x>=-11/18
-11/18≤x<2

Answer 2

忒简单了，加我百度好友这类问题直接问我

Answer 3

这人是咋了

Answer 4

我知道，但我不说

Answer 5

悬赏分太少，不做