解为5个连续整数的中间数
方程(1/x+3)-(1/x+4)=(1/x+6)-(1/x+7)的解为x=-5
1,[1/x-(n-k)]-……-[1/x-(n-2)]-[1/x-(n-1)]=[1/x-(n+1)]-[1/x-(n+2)-……-[1/x-(n+k)]的解为x=n(条件为k
(1) 1/(x-n) -1/(x-n-1)=1/(x-n-3)-1/(x-n-4) , 其解为x=n+2
(2) x=n+2= -5,得n= -7
故 1/(x+7) -1/(x+6)=1/(x+4) -1/(x+3)