1.x²+3x/x²+2x -x²-4/x²+4x+4 2.a²/a+b-a+b 3.(1-1/a-2)÷3-a/2a-4

题目

1.x²+3x/x²+2x -x²-4/x²+4x+4 2.a²/a+b-a+b 3.(1-1/a-2)÷3-a/2a-4
4.(x-1/y)÷（y-1/x) 5.3-x/x-4+1/4-x=1 6.x-2/x+2-1=3/x²-4 7.5/x-1=1/x+3
8.x+1/x-2+x+2/x-1=2

答案

1. x²+3x/x²+2x -x²-4/x²+4x+4
=x(x+3)/x(x+2)-(x+2)(x-2)/(x+2)²
=x+3-(x-2)/x+2
=5/x+2
2.a²/a+b-a+b= a²/2b
3.(1-1/a-2)÷3-a/2a-4
=0÷3-a/2a-4
=0
4.(x-1/y)÷（y-1/x)
=(x-1/y)(x/y-1)
=x/y
5.3-x/x-4+1/4-x=1
3-x/x-4 - 1/x-4=1
3-x-1/x-4=1
2-x=x-4
2x=6
x=3
6.x-2/x+2-1=3/x²-4
( x-2) ²/x²-4 -x²-4/x²-4=3/x²-4
(x-2) ²-(x²-4)=3
x²-2x+4-x²+4-3=0
-2x=-5
x=2/5
7.5/x-1=1/x+3
5(x+3)=x-1
5x+15=x-1
4x=16
x=4
8.x+1/x-2+x+2/x-1=2
(x+1)(x-1)+(x+2)(x-2)/(x-2)(x-1)=2
x²-1+x²-4/x²-3x+2=2
2x²-5=2(x²-3x+2)
2x²-5=2x²-6x+4
6x=9
x=3/2