We can use the distance formula to find the distance between two points.
[tex]\sqrt{(x.2 - x.1)^{2} + (y.2 - y.1)^{2}}[/tex]
√(-2 - 3)^2 + (-2 - 10)^2
√(-5)^2 + (-12)^2
√25 + 144
√169
13
The difference between the two points is 13 (like you said.)