20 (units)
Distance formula is:
Sqrt of (x-x1)^2+(y-y1)^2
So define which coordinate is (x,y) and what (x1,y1)
I’m going to define (-10,-7) as (x,y) and (2,9) as (x1,y1)
So plug in your variables!
Sqrt(-10-2)^2+(-7-9)^2
Sqrt-12^2+-16^2
Sqrt144+256
Sqrt400
So sqrt of 400 is 20! :))