Question

方程1/x-7-1/x-5-1/x-6-1/x-4的解是x=11/2,而7+5+6+4/4=11/2；方程1/x-7+1

Answer 1

1、 x=(a+d)/2

2、x-2分之x-1-【x-4分之x-3】=x-3分之x-2-【x-5分之x-4】

[(x-2)+1]/(x-2) -[(x-4)+1]/(x-4)=[(x-3)+1]/(x-3) -[(x-5)+1]/(x-5)

1 +1/(x-2) -1-1/(x-4) =1+1/(x-3) -1-1/(x-5)

1/(x-2)-1/(x-4)=1/(x-3) -1/(x-5)

∴x=7/2