1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I just want some clarification about the rules on solving quadratic equation. My question is coming from my solution for problem 49. Solving problem 49 Factor: (x−p−q)(√(x−q)+√(x−p))=0 Therefore: x−p−q=0⇒x=p+q this agrees with the answer in my book What Im confused about is the part where I divided out the lhs by (√(x−q)+√(x−p)). This factor contains x in it and I'm worried that I may have discarded the other root for the equation. And since it is a quadratic equation I am expecting to get two roots for the equation. Can you enlighten me about this matter? Thanks.