Answer:

Step-by-step explanation:
The magnitude of 3D vector
can be given by the following:

Plugging in given values, we have:
.
Move the x's to the same side
2x + x = 8 +6
then simplify
3x = 14
make x stand on its own
(3x)/3 = 14/3
the 3's on the x side cancel
x = 14/3