Vector equations!?

Question

Write the equation of the indicated sphere

Center (-2,1,-5)
radius sqrt(7)

Any help would greaty be appreciated thanks

Answer 1

This is not a vector.

radius of a sphere is similar to a circle

(x-a)² + (y-b)² + (z-c)² = r²

where (a,b,c) is the center and r is the radius, in your case:
(x + 2)² + (y - 1)² + (z + 5)² = 7

Answer 2

The equation of the sphere with center (h,p,k) and radius r is:

(x - h)² + (y - k)² + (z - p)² = r²

For the sphere at hand we have:

(x + 2)² + (y - 1)² + (z + 5)² = 7

Answer 3

(x+2)^2+(y-1)^2+(z+5)^2 = 7