作业帮几道分式求值 速度 马上就要
来源：学生作业帮 编辑：作业帮 分类：数学作业 时间：2024/05/16 07:46:42
几道分式求值 速度 马上就要
1. 1/x-y + 1/x+y + 2x/x^2+y^2 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
2. x-8/x-9 - x-7/x-8 - x-5/x-6 + x-4/x-5
3. 1/x^2+3x+2 + 1/x^2+5x+6 + 1/ x^2+4x+3
4. 1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3
5.x^2+2xy+y^2/x^2y+xy^2 - x^2-2xy+y^2/x^2-xy^2
谢谢各位大侠 小弟初来乍到 请多指教 好的追加分
1. 1/x-y + 1/x+y + 2x/x^2+y^2 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
2. x-8/x-9 - x-7/x-8 - x-5/x-6 + x-4/x-5
3. 1/x^2+3x+2 + 1/x^2+5x+6 + 1/ x^2+4x+3
4. 1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3
5.x^2+2xy+y^2/x^2y+xy^2 - x^2-2xy+y^2/x^2-xy^2
谢谢各位大侠 小弟初来乍到 请多指教 好的追加分
1.1/x-y + 1/x+y + 2x/x^2+y^2 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
原式＝ 2x/x^2-y^2 + 2x/x^2+y^2 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
=4x^3/x^4-y^4 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
=8x^7/y^8-x^8 + 8x^7/y^8-x^8
=16x^15/(y^16-x^16)
2.x-8/x-9 - x-7/x-8 - x-5/x-6 + x-4/x-5
原式= (x^2-16x+64)-(x^2-16x+63)/(x-9)(x-8) - (x^2-10x+25)-(x^2-10x+24)/(x-6)(x-5)
= 1/(x-9)(x-8) - 1/(x-6)(x-5)
= (x^2-11x+30)-(x^2-17x+72)/(x-9)(x-8)(x-6)(x-5)
=(6x-42)/(x-9)(x-8)(x-6)(x-5)
3.1/x^2+3x+2 + 1/x^2+5x+6 + 1/ x^2+4x+3
原式＝1/(x+1)(x+2) + 1/(x+2)(x+3) + 1/(x+1)(x+3)
=(x+3+x+1+x+2)/(x+1)(x+2)(x+3)
=3(x+2)/(x+1)(x+2)(x+3)
=3/(x+1)(x+3)
4.1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3
5.x^2+2xy+y^2/x^2y+xy^2 - x^2-2xy+y^2/x^2-xy^2
原式＝（x+y）^2/xy(x+y) - (x-y)^2/x(x-y)
=x+y/xy - x-y/x
=(x+y-xy+y^2)/xy
这些题出得乱七八糟
再问： 确实够乱的，但是大侠，亲 我只能依靠你啦！
再答： 4. 1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3 原式＝1/x^2+2x-1 + 1/x^2+2x+3 - 2/x^2+2x+1 ＝1/x^2+2x+1-2 + 1/x^2+2x+1+2 - 2/x^2+2x+1 ＝x^2+2x+1+2+x^2+2x+1-2/(x+1)^4-4 - 2/x^2+2x+1 ＝2(x+1)^2/(x+1)^4-4 - 2/(x+1)^2 =2(x+1)^4-2(x+1)^4+8/(x+1)^6-4(x+1)^2 =8/[(x+1)^6-4(x+1)^2]
原式＝ 2x/x^2-y^2 + 2x/x^2+y^2 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
=4x^3/x^4-y^4 + 4x^3/x^4+y^4 + 8x^7/y^8-x^8
=8x^7/y^8-x^8 + 8x^7/y^8-x^8
=16x^15/(y^16-x^16)
2.x-8/x-9 - x-7/x-8 - x-5/x-6 + x-4/x-5
原式= (x^2-16x+64)-(x^2-16x+63)/(x-9)(x-8) - (x^2-10x+25)-(x^2-10x+24)/(x-6)(x-5)
= 1/(x-9)(x-8) - 1/(x-6)(x-5)
= (x^2-11x+30)-(x^2-17x+72)/(x-9)(x-8)(x-6)(x-5)
=(6x-42)/(x-9)(x-8)(x-6)(x-5)
3.1/x^2+3x+2 + 1/x^2+5x+6 + 1/ x^2+4x+3
原式＝1/(x+1)(x+2) + 1/(x+2)(x+3) + 1/(x+1)(x+3)
=(x+3+x+1+x+2)/(x+1)(x+2)(x+3)
=3(x+2)/(x+1)(x+2)(x+3)
=3/(x+1)(x+3)
4.1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3
5.x^2+2xy+y^2/x^2y+xy^2 - x^2-2xy+y^2/x^2-xy^2
原式＝（x+y）^2/xy(x+y) - (x-y)^2/x(x-y)
=x+y/xy - x-y/x
=(x+y-xy+y^2)/xy
这些题出得乱七八糟
再问： 确实够乱的，但是大侠，亲 我只能依靠你啦！
再答： 4. 1/x^2+2x-1 - 2/x^2+2x+1 + 1/x^2+2x+3 原式＝1/x^2+2x-1 + 1/x^2+2x+3 - 2/x^2+2x+1 ＝1/x^2+2x+1-2 + 1/x^2+2x+1+2 - 2/x^2+2x+1 ＝x^2+2x+1+2+x^2+2x+1-2/(x+1)^4-4 - 2/x^2+2x+1 ＝2(x+1)^2/(x+1)^4-4 - 2/(x+1)^2 =2(x+1)^4-2(x+1)^4+8/(x+1)^6-4(x+1)^2 =8/[(x+1)^6-4(x+1)^2]