You reverse the inequality when you divide both sides by a negative number. example: -5x>45 (you divide both sides here by -5 to get the value of x) answer: x<9 (notice inequality has been has been reversed)
We can solve inequalities to find all values of the variable that make the inequality true. The idea is to get the variable all by itself on one side of the inequality sign so we can easily see the solutions to the inequality.
Hence for any given inequality and for any given number if we put that number in that inequality and see that the given inequality sign holds true than that number will be a solution of the inequality otherwise it is not an solution of the inequality.