How to do distance formulas

I am studing for my ACT test and these are one of the easist questions to get right if you know the formula.

sqrt((x-x)^2+(y-y)^2

you just input the numbers into the given spaces, but this is how it would look on //web2.0calc.com

Look through this

http://www.mathsisfun.com/algebra/distance-2-points.html