Question

数学题啊啊啊！！

x/x-1-x/x的平方-1
化简啊化简!!是分式的内容！！
12/m的平方-9+2/3-m
化简啊化简!!要过程!!是分式的内容
4a-2a+2/a(a+1)(a-1)
化简啊化简!!要过程!!是分式的内容啊!!

Answer 1

【参考答案】

1、[x/(x-1)]-[x/(x²-1)]
=[x(x+1)/(x²-1)]-[x/(x²-1)]
=[x(x+1)-x]/(x²-1)
=x²/(x²-1)

2、[12/(m²-9)]-[2/(3-m)]
=[12/(m²-9)]+[2(m+3)/(m²-9)]
=[12+2(3+m)]/(m²-9)
=(2m+18)/(m²-9)

3、4a-[(2a+2)/a(a+1)(a-1)]
=4a-[2(a+1)/a(a+1)(a-1)]
=4a-[2/a(a-1)]
=[4a²(a-1)/a(a-1)]-[2/a(a-1)]
=(4a³-4a²-2)/(a²-a)

Answer 2

解设2008年6月底的网民人数是X万人
1.9x
＋430 ＝48500
1.9x
＝48500－430
1.9X
＝48070
X＝25300
2008年6月底的网民人数是25300万人，合2.53亿人。

Answer 3

1、[x/(x-1)]-[x/(x²-1)]
=[x(x+1)/(x²-1)]-[x/(x²-1)]
=[x(x+1)-x]/(x²-1)
=x²/(x²-1)
2、[12/(m²-9)]-[2/(3-m)]
=[12/(m²-9)]+[2(m+3)/(m²-9)]
=[12+2(3+m)]/(m²-9)
=(2m+18)/(m²-9)
3、4a-[(2a+2)/a(a+1)(a-1)]
=4a-[2(a+1)/a(a+1)(a-1)]
=4a-[2/a(a-1)]
=[4a²(a-1)/a(a-1)]-[2/a(a-1)]
=(4a³-4a²-2)/(a²-a)

Answer 4

1、[x/(x-1)]-[x/(x²-1)]
=[x(x+1)/(x²-1)]-[x/(x²-1)]
=[x(x+1)-x]/(x²-1)
=x²/(x²-1)

2、[12/(m²-9)]-[2/(3-m)]
=[12/(m²-9)]+[2(m+3)/(m²-9)]
=[12+2(3+m)]/(m²-9)
=(2m+18)/(m²-9)

3、4a-[(2a+2)/a(a+1)(a-1)]
=4a-[2(a+1)/a(a+1)(a-1)]
=4a-[2/a(a-1)]
=[4a²(a-1)/a(a-1)]-[2/a(a-1)]
=(4a³-4a²-2)/(a²-a)