4x-1.5 2.5x=-15

是这样的：x^5+x^4=x^3(x^2+x)=(x^2+x)[(x^3-1)+1]=(x^2+x)(x^3-1)+x^2+x=[x(x+1)(x-1)](x^2+x+1)+x^2+x=(x^3-x)

x-y+5x-4x=2x-y

设a=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)那么y=a*(x-10);那么y^=a^*(x-10)+a*(x-10)^=a^*(x-10)+a那么y

 再问：额、不懂再答： 再答：后面的看做一个整体再问：好的吧、谢谢大神再答：回来的话，请采纳再问：啊、突然明白了呢。。。

[1-1/(x-4)]+[1-1/(x-8)]=[1-1/(x-7)]+[1-1/(x-5)]1/(x-4)+1/(x-8)=1/(x-7)+1/(x-5)(x-4+x-8)/(x-4)(x-8)=(

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550120x=550x=55/12=4.583

x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊

2x+3x+4x+5x+x+6x+7x=10028x=100x=100/28x=25/7

x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=（x+x^2+x^3+x^4）+（x^5+x^6+x^7+x^8）=x（1+x+x^2+x^3）+x^5（1+x+x^2+x^3）=（x+x

15x=23x-248x=24x=312+5x=3x-82x=-20x=-103(x-3)=9-(x+6)4x=9+9-6=12x=34+x=4x-173x=21x=7

即x²-5x=-1所以原式=x³-5x²+x²-5x+x-1=x(x²-5x)+(x²-5x)+x-1=-x-1+x-1=-2

即1/(x-5)+1/(x-9)=1/(x-6)+1/(x-8)(2x-14)[1/(x-5)(x-9)-1/(x-6)(x-8)]=01/(x-5)(x-9)-1/(x-6)(x-8)≠0所以2x-

/>(4X+2)/X+【4(X-5)-2】/(X-5)=【(X-4)-2】/(X-4)+【7(X+1)+2】/(X+1)4+2/X+4-2/(X-5)=1-2/(X-4)+7+2/(X+1)8+2/X

设x1=4-√3,x2=4+√3,是方程X^2-8X+13=0的两根所以X1^2-8X1+15=2X^4-6X^3-2X^2+18X+23=(X+1)^2*(X^2-8X+13)+10=10所以原式=

4x+18=5x-1518+15=5X-4X33=X

前面那些看不懂.-1.5x=18*2-1.5x=36x=-24再问：x=4x=2545x-x=1803x+x=1615x-11x=12.8(12+12*1.5)x=3603.5(85=X)=560(x

∵(x^4-4x^2+5x-15)/[(x^2+1)(x-2)]=[(x^4+x²-5x²-5)+(5x-10)]/[(x²+1)(x-2)]=[x²(x&su

(X-4)/(X-5)-(X-5)/(X-6)=(X-7)/(X-8)-(X-8)/(X-9)[(x-4)(x-6)-(x-5)2]/(x-5)(x-6)=[(x-7)(x-9)-(x-8)2]/(x

x^2-2x+1=15(x-1)^2=15x=正负根号15+1x(2x-5)=4x-102x^2-5x-4x+10=02x^2-9x+10=0(2x-5)(x-2)=0x=5/2或x=2x^2+5x+

15-4+5X=2X+35-3X11+5X-2X+3X=356X=35-116X=24X=4