I think the best approach to solve the middle question is to substitute and eliminate the 5 answer choices to the equation in the ques which comes out to be as x=-2.
Great video-- very insightful principles and examples! I'm curious, under what circumstances do you advise reviewing an unofficial explanation, and from which source? (for example, Manhattan GMAT Navigator, or a GMAT Club question search). I know for many verbal questions, you've posted outstanding explanations on GMAT Club.
Thank you for the kind words about our explanations, Ben! Honestly, a lot of non-official explanations suffer from the same problems that Mike describes in the video: some are great, others not so much -- and no source is perfect, so we won't endorse any here. If you can avoid relying on written explanations (even ours!) by following the steps in the video, that's ideal. If you feel that you absolutely have to spend your precious study time reading non-official explanations, then I guess you'll want to use whichever source seems to resonate best with you -- but again, I think it's best to use them sparingly, for the reasons Mike lays out in the video.
