Tìm x biết: 1/x(x + 1) + 1/(x + 1).(x + 2) + 1/(x + 2).(x + 3) - 1/x = 1/2010

tìm x biết
a ) 1/x(x+1) + 1/(x+1).(x+2) + 1/(x+2).(x+3) - 1/x = 1/2010
dau / la dau phan so nha