Hey there! I'm happy to help!
To find the distance between two points, you find the difference between the x values, square that, find the difference between the y values, square that, add the two numbers you got, and then find the square root.
We find the difference between the x-values.
-4--2
-4+2=-2
Square it
-2²=4
We find the difference of the y-values.
-1--3
-1+3=2
Square it
2²=4
We add these two numbers we got.
4+4=8
And we find the square root.
√8≈2.828
Have a wonderful day! :D