You can put this solution on YOUR website! (1+(1/(x+3)) (1+(1/(x+2)) (1+(1/(x+1))
rewrite as
(x+4)/(x+3)*(x+3)/(x+2)*((x+2)/(x+1); we can do that, because the first is (x+3)/(x+3)+ (1/(x+3))
Everything cancels except (x+4)/(x+1), which is the answer.