由 訪客 於 星期三 一月 25, 2006 11:05 pm
3/x+1/(x-1)+4/(x-2)+4/(x-3)+1/(x-4)+3/(x-5)=0
3/x+3/(x-5)+1/(x-1)+1/(x-4)+4/(x-2)+4/(x-3)=0
3(2x-5)/(x^2-5x)+(2x-5)/(x^2-5x+4)+4(2x-5)/(x^2-5x+6)=0
(2x-5)[3/( x^2-5x)+1/ (x^2-5x+4)+4/( x^2-5x+6)]=0
2x-5=0,x=5/2
or
3/( x^2-5x)+1/ (x^2-5x+4)+4/( x^2-5x+6)=0
a=x^2-5x
3/a+1/(a+4)+4/(a+6)=0
3(a^2+10a+24)+a^2+6a+4(a^2+4a)=0
8a^2+52a+72=0
a=-2,-9/2
x^2-5x+2=0
x=(5+-根號17)/2
x^2-5x+9/2=0
x=(5+-根號7)/2