determine the midpoint of the segment whose endpoints are a(7 3 -4) and b(-3 1 0)

Answer 1

Do you mean: A(7,3.-4), B(-3,1,0).
If so,

X = (7+(-3))/2 = 2.
Y = (3+1)/2 = 2.
Z = (-4+0)/2 = -2.

(x,y,z) = (2,2,-2).