作业帮5x 2>3(x-1),1 2x
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/22 02:50:52
原式=-x-2，当x=12时，原式=-12-2=-212．
原式=x³-6x²-9x-2x²+12x+18-（x²-5x）（x-3）=x³-8x²+3x+18-（x³-3x²-5x
后面的x²＋11x－708有误吧!再问：没有题目就这样能不能帮我再答：那我就试试：原式为：1/x2+x+1/x2+3x+2+1/x2+5x+6+1/x2+7x+12+1/x2+9x+20=5
把x2+5x看成是一个未知数Y,就可以解了
原式=(x²+3x+9)/(x-3)(x²+3x+9)-6x/x(x-3)(x+3)-(x-1)/2(x+3)=1/(x-3)-6/(x-3)(x+3)-(x-1)/2(x+3)=
原式=[1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)]×(x+4)(x+5)=[1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+1/(x+3)-1/(x
1/(x²+3x+2)=[(x+2)-(x+1)]/(x+1)(x+2)=1/(x+1)-1/(x+2)同理1/(x²+5x+6)=1/(x+2)-1/(x+3)1/(x²
1/(x2-5x+6)-1/(4x-x2-3)-1/(3x-x2-2)=1/(x2-5x+6)+1/(x2-4x+3)+1/(x2-3x+2)=1/(x-2)(x-3)+1/(x-3)(x-1)+1/
你可以参见“韦达定理”方程两个根的积是1,说明他们互为倒数.x^2+1/x^2=(x+1/x)^2-2*x*1/x=（-5）²-2=23
直接写答案?再问：要写过程，再答：好了哦，给采纳一下吧
5x(x2-3x-1)-x2(1-x)=5x^3-15x^2-5x-x^2+x^3=6x^3-16x^2-5x
x/x²-3x+1=1/5x²-3x+1=5xx²+1=8xx+1/x=8平方x²+2+1/x²=64x²+1/x²=62x
答：x²-5x=3(x-1)(2x-1)-x(x+3)+15/(x²-3)=2x²-3x+1-x²-3x+15/(5x)=x²-5x-x+1+3/x=
=1/(x-2)(x-1)+1/(x-2)(x-3)+1/(x-3)(x-4)-4/(x-1)(x-5)帮你删除了1/x2-7=1/(x-2)-1/(x-1)+1/(x-3)-1/(x-2)+1/(x
1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)=1/x-1/
5x²－3x－5＝0△＝3²－4×5×(－5)＝109x＝[﹣(﹣3)±√109]/5由原方程可得所求式子＝(x＋5)－1/(x＋5)所求式子＝(118±6√109)/25－25/
（1）∵x2-5x-24=0∴（x-8）（x+3）=0，解得：x=8，或x=-3，（2）∵7x（5x+2）=6（5x+2）∴（7x-6）（5x+2）=0，解得：x=67，或x=-25，（3）∵x2+1
原式=-2x2+3x-5x+2x2+1+x2=x2-2x+1．
如果是12的话就没有办法分解了,对不起（X^2+3x+2）(x^2+7x+12)-120=(x+1)(x+2)(x+3)(x+4)-120=(X^2+5x+4）(x^2+5x+6)-120=(X^2+
(x+1)²-2(x²-1)+(x-1)²=(x+1)²-2(x+1)(x-1)+(x-1)²=[(x+1)-(x-1)]²=2²