yes im new so pls excuse if i do something wrong but,

I have an exam in eight hours and im panicking because im really tired.

Essentially, ive forgotten how to calculate distance in C/G (Coordinate Geometry) Puzzled with the first revision question already:

Find the distance between R(-1, 5) and S(2, -1)

the formula is:

Could someone please walk me through the process of working this out? thankyoou so much!