1. The problem statement, all variables and given/known data Solve the inequality -9 < 1/x A simple inequality, I can see the solution is just x < -1/9 but I can't prove it at all. 3. The attempt at a solution -9 < 1/x -9x < 1 x > -1/9 Any helpful rules I am forgetting about inequalities? This was a problem in a review from high school set provided by my instructor for my introductory math class. Just curious about a solution, it's a calculus course that doesn't really test on this sort of thing but I figure I should actually try and figure out these basic things.