Let u = [3,−4] and v = [8, 15]. Calculate the four numbers |u|, |v|, |u − v|, and |u| − |v|. Do the same with the vectors u = [2, 6,−3] and

Question

v = [2, 2, 1].

Answer 1

if w = [a,b]
then |w| = √(a^2 + b^2)

so |u| and |v| are easy

u - v =[3,-4] - [8,15]
= [-5,-19]

now apply the above formula again

the same rules apply to the 3-D vectors.
Post your answers so I can check them

Answer 2

will do. thanks