Question

急！几道有关分式加减乘除的题目！

计算2/X-1 - (1-3X)/2-2X结果
计算a-b+2b²/a+b=
化简(1-1/a-2)÷3-a/2a-4
已知a+b=3,ab=1,则a/b+b/a=
化简（x-1/y）÷（y-1/x)=
若x等于它的倒数，则x²-4x+4/x+3÷ x-2/x²+6x+9
在线等！

Answer 1

2/(X-1) - (1-3X)/(2-2X)
= 2/(X-1) + (1-3X)/{2(X-1)}
= ( 2*2+1-3X)/{2(X-1)}
= (5-3X) / {2(X-1)}

a-b + 2b^2 / (a+b)
= {(a-b)(a+b)+2b^2} / (a+b)
= {a^2-b^2+2b^2) / (a+b)
= (a^2+b^2)/(a+b)

{(1-1/(a-2)}÷(3-a)/(2a-4)
=(a-2-1)/(a-2) * 2(a-2)/{-(a-3)}
=-(a-3)/(a-2) * 2(a-2)/(a-3)
=-2

a+b=3,ab=1
a/b+b/a
=(a^2+b^2)/(ab)
={(a+b)^2-2ab}/(ab)
={3^2-2*1} / 1
=7

（x-1/y）÷（y-1/x)
= (xy-1)/y ÷ （xy-1)/x
=xy

x=1/x
x^2=1
x=±1
(x²-4x+4)/(x+3) ÷ (x-2)/(x²+6x+9)
= (x-2)^2/(x+3) * (x+3)^2/(x-2)
= (x+3)(x-2)
= x^2 + x - 6
= 1+x-6
= x-5
= ±1-5
= -6，或-4

Answer 2

2/(x-1)-(1-3x)/(2-2x)
=4/(2x-2)-(1-3x)/(2-2x)
=4/(2x-2)+(1-3x)/(2x-2)
=[4+(1-3x)]/(2-2x)
=(5-3x)/(2x-2)

a-b+2b²/(a+b)
=(a-b)(a+b)/(a+b)+2b^2/(a+b)
=(a^2-b^2)/(a+b)+2b^2/(a+b)
=(a^2-b^2+2b^2)/(a+b)
=(a^2+b^2)/(a+b)

[1-1/(a-2)]÷(3-a)/(2a-4)
=[(a-2)/(a-2)-1/(a-2)]÷(3-a)/(2a-4)
=[(a-2-1)/(a-2)]÷(3-a)/(2a-4)
=(a-3)/(a-2)÷(3-a)/(2a-4)
=(a-3)/(a-2)*(2a-4)/(3-a)
=(a-3)/(a-2)*2(a-2)/(3-a)
=2(a-3)/(3-a)
=-2(a-3)/(a-3)
=-2

a/b+b/a
=(a^2+b^2)/ab
=[(a^2+2ab+b^2)-2ab]/ab
=[(a+b)^2-2ab]/ab
=[3^2-2*1]/1
=9-2
=7

(x-1/y)÷（y-1/x)
=(xy/y-1/y)÷（xy/x-1/x)
=[(xy-1)/y]÷[(xy-1)/x]
=(xy-1)/y*x/(xy-1)
=x/y

x=1/x
x^2=1
x=±1

(x²-4x+4)/(x+3)÷ (x-2)/(x²+6x+9)
=(x-2)²/(x+3)÷ (x-2)/(x+3)²
=(x-2)²/(x+3)* (x+3)²/(x-2)
=(x-2)(x+3)
=x^2+x-6
=1+x-6
=x-5

当x=-1时,x-5=-1-5=-6
当x=1时,x-5=1-5=-4

追问

麻烦啦
-3m²/4n²÷3m/an四次方÷（-m五次方/4n²）

Answer 3

解：1、2/(X-1) - (1-3X)/(2-2X)
= 2/(X-1) + (1-3X)/{2(X-1)}
= ( 2*2+1-3X)/{2(X-1)}
= (5-3X) / {2(X-1)}

2、a-b + 2b^2 / (a+b)
= {(a-b)(a+b)+2b^2} / (a+b)
= {a^2-b^2+2b^2) / (a+b)
= (a^2+b^2)/(a+b)

3、{(1-1/(a-2)}÷(3-a)/(2a-4)
=(a-2-1)/(a-2) * 2(a-2)/{-(a-3)}
=-(a-3)/(a-2) * 2(a-2)/(a-3)
=-2

4、a+b=3,ab=1
a/b+b/a
=(a^2+b^2)/(ab)
={(a+b)^2-2ab}/(ab)
={3^2-2*1} / 1
=7

5、（x-1/y）÷（y-1/x)
= (xy-1)/y ÷ （xy-1)/x
=xy

6、x=1/x
x^2=1
x=±1
(x-4x+4)/(x+3) ÷ (x-2)/(x+6x+9)
= (x-2)^2/(x+3) * (x+3)^2/(x-2)
= (x+3)(x-2)
= x^2 + x - 6
= 1+x-6
= x-5
= ±1-5
= -6，或-4
希望能给你帮助!

追问

-3m²/4n²÷3m/an四次方÷（-m五次方/4n²）
麻烦你了