I was told that when undoing operations in an equation you should start by following the PEDMAS rules, but in reverse. So, for example:
8x + 16/x = 4x + 16
According to the advice, I should start this problem by subtracting 16/x, since addition is the first operation to perform if your following PEDMAS backwards. However, online solvers of this problem perform multiplication first (by multiplying everything on both sides by x) in order to undo the division. I have seen similar problems solved in the same way, with the undoing of division being the first operation. My question is when is it your suppose to apply the reverse PEDMAS rule? Or does that rule really matter?