1/(X+1)-1/(X+4)=1/(X+2)-1/(X+3)
首相,分母不為零：X+1≠0,X+4≠0,X+2≠0,X+3≠0
即x≠-1,-2,-3,-4
兩邊分別通分：
(x+4-x-1) / [(X+1)(X+4)] = (x+3-x-2) / [(X+2)(X+3) ]
3 / [X^2+5x+4] = 1 / [X^2+5X+6 ]
X^2+5x+4 = 3(X^2+5X)+18
2(X^2+5X)+14=0
X^2+5X+7=0
判別式=5^2-4*7=-3＜0,無實數(shù)解
在復(fù)數(shù)范圍內(nèi)：
x=-5/2 ± 根號3/2 i