1. The problem statement, all variables and given/known data in this question , solving equation 1 and 2 , how to get the F1 = (A1E1 P ) / ( 2A1E1 + A2E2) ? and also F2 ? 2. Relevant equations 3. The attempt at a solution we know that F2 = P -2F1 ) I have tried to sub (F2 / A2E2 ) in F1 = (A1E1 P ) / ( 2A1E1 + A2E2) , but i ended up getting (A1E1P - 3 F1A1E1 ) / A2E2 , which is not same as the author , did i miss out any equation ?