Question

问一些数学题 1. (a²/a²-4)÷(a/a+2) 2. (a+1/a-1)-(a²+a/a-1)

3. (3x+6/x²+4x+4)÷(x-2/x+2)-(1/x-2)
4. (x-1/x)÷[x-(1/x)]
5. (1/m+1/n)÷(m+n/n)
6. [1-(1/1-a)] (1/a²-1)
7. [(x+2/x²-2x)-(x-1/x²-4x+4)]÷(x-4/x)
8. [(x-2/x+2)-(4x/x²-4)]÷(1/x²-4)
答对加悬赏

Answer 1

(a²/a²-4)÷(a/a+2)
=a²/(a+2)(a-2)x(a+2)/a
=a/(a-2)

(a+1/a-1)-(a²+a/a-1)
=(a+1-a²-a)/(a-1)
=(1+a)(1-a)/(a-1)
=-a-1

(3x+6/x²+4x+4)÷(x-2/x+2)-(1/x-2)
=3(x+2)/(x+2)²*(x+2)(x-2)-1/(x-2)
=3(x-2)-1/(x-2)
=[3(x-2)²-1]/(x-2)
=(3x²-12x+11)/(x-2)

(x-1/x)÷[x-(1/x)]
= (x-1/x)÷[(x-1)(x+1)/x)]
=(x-1)/x*x/(x-1)(x+1)
=1/(x+1)

(1/m+1/n)÷(m+n/n)
=(m+n)/mnxn/(m+n)
=1/m

[1-(1/1-a)] (1/a²-1)
=(1-a-1)/(1-a)x(1/a+1)(1/a-1)
=a/(a-1)x(1/a+1)(1/a-1)
=a(1/a+1)(1/a-1)/(a-1)

不解了太多了~
祝学习进步，望采纳~~

Answer 2

1. (a²/a²-4)÷(a/a+2)
=[a/(a+2)*a/(a-2)]÷(a/a+2)
=a/(a-2)]

2. (a+1/a-1)-(a²+a/a-1)
=(a+1-a²)/(a-1)

3. (3x+6/x²+4x+4)÷(x-2/x+2)-(1/x-2)
=2(x+2)/(x+2)²×(x+2)/(x-2)-1/(x-2)
=1/(x-2)

4. (x-1/x)÷[x-(1/x)]
=(x-1)/x *x/[(x-1)(x+1)]
=1/(x+1)

5. (1/m+1/n)÷(m+n/n)
=(m+n)/mn*n/(m+n)
=1/m
6. [1-(1/1-a)] (1/a²-1)
=-a/(1-a)*(1+a)(1-a)/a
=-(a+1)
=-a-1

7. [(x+2/x²-2x)-(x-1/x²-4x+4)]÷(x-4/x)
=[(x+2)/[x(x-2)]-(x-1)/(x-2)²]*x/[(x+2)(x-2)]
=1/(x-2)²-x(x-1)/(x-2)³(x+2)

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

Answer 3

1. (a²/a²-4)÷(a/a+2)= (a²/a²-4)*(a+2/a) =a/a-2
2. (a+1/a-1)-(a²+a/a-1)=-(a +1)
3. (3x+6/x²+4x+4)÷(x-2/x+2)-(1/x-2)=3/(x+2)*(x+2)/(x-2)-(1/x-2)=2/(x-2)
4. (x-1/x)÷[x-(1/x)]=1
5. (1/m+1/n)÷(m+n/n)=(m+n)/mn*n/(m+n)=1/m
6. [1-(1/1-a)] (1/a²-1)=a/(a-1)(1/a-1)(1/a+1)
7. [(x+2/x²-2x)-(x-1/x²-4x+4)]÷(x-4/x)
=[x+2/x(x-2)-(x-1)/(x-2) (x-2)]*x/(x-4)
=(x-4)/x(x-2)(x-2)*x/(x-4)
=1/(x-2)(x-2)
8. [(x-2/x+2)-(4x/x²-4)]÷(1/x²-4)=x²-8x+4

Answer 4

1 a/(a-1)
2 -1-a
3 2/(x-2)
4 1/(x+1)
5 1/m
6 -(a+1)/a
7 .....