方程x²-4x-1=0的解-搜答案-拍题作业网

4x^2-3x-1=0(4x+1)*(x-1)=0x=-1/4..x=1

4/(x-2)+(x-1)/[(x-2)(x-3)]-2/(x-3)=0[4(x-3)+(x-1)-2(x-2)]/[(x-2)(x-3)]=03(x-3)/[(x-2)(x-3)]=0不知道解了~~

由题意可知：x≠-1且x≠0而方程x²-3x-4=0可化为：(x-4)(x+1)=0解得：x=4（另x=-1不合题意,舍去）所以：(x²-2x)/(x+1)·(1+1/x)=x(x

(x/x(x+2))+(x/(x+2)(x+4))+.+x/(x+8)(x+10)=(x/2)*(2/x(x+2))+(2/(x+2)(x+4))+.+2/(x+8)(x+10)=(x/2)*[1/x

【解法一】【解法二】5x(x+7)(x+4)=5x(x^2+11X)5x(x²+11x+28)-5x(x²+11x)=05x^3+55x^2+140x=5x^3+55x^25x(x

X的平方-2X-1=0x=[2±√(2^2-4*1*(-1)]/2=(2±2√2)/2=1±√2x=1+√2或x=1-√2

4(123-x)=57+x492-4x=57+xx+4x=492-575x=435x=87

intf(floatx)返回值,错了.

3x/(x+1)-(x+4)/(x^2+x)=-23x^2-(x+4)=-2(x^2+x)3x^2-x-4=-2x^2-2x5x^2+x-4=0(5x-4)(x+1)=0x1=4/5x2=-1经检验,

2/x^2+x+3/x^2-x-4/x^2-1=0(2/x^2+3/x^2-4/x^2)+x-x-1=01/x^2-1=01/x^2=1x^2=1x=1或-1

简单的分类讨论：x²-4x+8=0,无解【b²-4ac＜0】一般c太大,都是无解的、x²-4x=0,x1=4x2=0即为最终答案、楼主!

x(x+1)(x²-2x-4)=0x1=0x2=-1x²-2x-4=0x²-2x+1=5(x-1)²=5x3=1+√5x4=1-√5x³-2x+1=0

x^2-4x-1=0(x^2-4x+4)-5=0(x-2)^2=5x=5开根号+2或-5开根号+2

这题如果x>1/3且x

答：x²-3x-3/x+1/x²+4=0两边同乘以x²得：x^4-3x³+4x²-3x+1=0(x-1)(x³-2x²+2x-1)

3x²=4x-13x²-4x+1=0(3x-1)(x-1)=0x=1/3或x=1

x=-1是方程x^2-4x=5x+10的解将x=-1代入,左右两边都等于5

设t=|x|t≥0那么原方程可以等价转化成t²-t-1=0得t=（1+√5）/2所以方程的解是x=±[（1+√5）/2]

由题易知x

X²-3X-1=0X²-3X=1X²-3X+9/4=1+9/4(x-3/2）²=13/4x-3/2=正负根号13/2x1=(3+根号13）/2或x2=(3-根号