Answer:
5 units
Explanation:
±√(- 2 - 1)^2 + (- 1 - 3)^2 = ±5 (rej - 5 since distance > 0)
Apply distance formula
This is a topic on coordinate geometry. If you would like to find out more you can give my Instagram page a follow as I'll be updating on this topic soon. In addition, I will be posting other useful materials created by myself at the same platform too!