Find the distance between G point a and point H

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Which zero pair could be added to the function f(x) = x2 + 12x + 6 so that the function can be written in vertex form? o 3, -3o 6,629,-936, 36