1. The problem statement, all variables and given/known data Not sure if I'm posting in the right area. Stuck on this question. 1/a + 1/ab + 1/abc = 25/84 Find the value of a+b+c 2. Relevant equations 3. The attempt at a solution I tried making abc = 84 then bc+c +1 = 25 but still couldn't solve it.