This is the distance formula. Lets say you have two points. One is (3,4), and the other is (2,3).
First, you would take the numbers and plug them into the formula. That is done by the order of the numbers, as seen in the picture.
Second, solve the formula, simply by subtracting the parenthesis, then squaring the numbers and adding them.
That's it! You have your distance! In this example, the answer was 2. Make sure to label your answer with the correct type of unit.