You undo the order of operations (PEMDAS) to isolate x. In other words, we follow PEMDAS backwards. We undo subtraction first, then undo addition, etc etc. The inequality sign will flip when you divide both sides by a negative number
-2x + 3 < 5
-2x +3-3 < 5-3 ... subtract 3 from both sides
-2x < 2
-2x/(-2) > 2/(-2) .... divide both sides by -2; inequality sign flips
x > -1
Therefore the answer is x > -1 meaning x can be any number larger than -1. So something like x = 0 is a solution but x = -2 is not.
To represent all of the solutions in terms of a graph, you plot an open unfilled circle at -1 on the number line. Then shade everything to the right of that open circle. The open circle tells the reader "do not include this value as part of the solution set". So x = -1 is not in the solution set.
