1.(x^3-x^2-4x+1)/(x^2-3x+2)-(x^3-2x^2-9x+21)/（x^2-5x+6）+（x^2

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/09/23 20:20:55

1.(x^3-x^2-4x+1)/(x^2-3x+2)-(x^3-2x^2-9x+21)/（x^2-5x+6）+（x^2-3x+8）/（x^2-4x+3）
2.{(x^2)/（x-y)}*{y/(x+y)}-{(x^4y)/(x^4-y^4)}÷{（x^2/x^2+y^2）^2}

1.将3个分数化成6个,当然其中要有一定的技巧分配.
看分母是(x-1)(x-2)(x-3)的组合,所以想到将分子也配成这样的来化简：[(x^3-4x)-(x^2-1)]/[(x-2)(x-1)] - [(x^3-4x^2+4x)+(2x^2-13x+21)]/[(x-2)(x-3)] + [(x^2-7x+12)+(4x-4)]/[x-3)(x-1)]
= [x(x+2)(x-2)-(x+1)(x-1)]/[(x-2)(x-1)] - [x(x-2)^2+(2x-7)(x-3)]/[(x-2)(x-3)] + [(x-3)(x-4)+4(x-1)]/[x-3)(x-1)]
想式子化简成6个只有1个分母的式子：[x(x+2)]/(x-1) - (x+1)/(x-2) -[x(x-2)]/(x-3) - (2x-7)/(x-2) + (x-4)/(x-1) + 4/(x-3)
再将分母相同的组合在一起：[x(x+2)+(x-4)]/(x-1) - [(x+1)+(2x-7)]/(x-2) -[x(x-2)-4]/(x-3)
=(x^2+3x-4)/(x-1) - (3x-6)/(x-2) - (x^2-2x-4)/(x-3)
=[(x-1)(x+4)]/(x-1) - [3(x-2)]/(x-2) - [(x^2-2x-3)-1]/(x-3)
=(x+4)- 3 - [(x+1)(x-3)-1]/(x-3)
=x+1 - {[(x+1)(x-3)]/(x-3)-1/(x-3)}
=x+1-{(x+1)-1/(x-3)
=1/(x-3)
2. 这个题觉得你写的可能会出现歧义,我是以以下式子
{(x^2)/(x-y)}*{y/(x+y)}-{(y*x^4)/(x^4-y^4)}÷{(x^2)/(x^2+y^2)^2}
=(y*x^2)/(x^2-y^2) - {(y*x^4)/[(x^2+y^2)(x^2-y^2)]} × {[(x^2+y^2)^2]/(x^4)}
对后面式子进行化简,主要是约分(如果这样不好看请自己将上式用分数写下来)：
=(y*x^2)/(x^2-y^2) - {y(x^2+y^2)}/(x^2-y^2)
=(y*x^2)/(x^2-y^2) - {(y*x^2)/(x^2-y^2)+(y^3)/(x^2-y^2)}
= -(y^3)/(x^2-y^2)

|X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10| x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4 x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x （1） x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8 约分 (X的平方+4x+3)(2x-x)^/(X^+X)(X^+X-6), y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 设函数f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10), 已知 X=4- 根号3 求 (X*X*X*X-6X*X*X-2X*X+18X+23) / (X*X-8X+15)的值计算（x*x+4x+5）/（x+2）-（x*x+6x+10）/（x+3）+1 x/x-3-5x/x^2-x-6计算 x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2)