I have the following code
o = {Red, PointSize[.03], Point[orig = {0, 0, 0}]};
u = {2, a, -1};
v = {3, 1, -2};
w = {2 a - 1, -2, 4};
Solve[Dot[u, v] == Dot[u + v, v + w], a]
a = a /. Flatten[%];
Graphics3D[{Text[Style["u", Large, Bold, Red], Offset[{-50, -30, 0}, u]],
Text[Style["v", Large, Bold, Red], Offset[{-50, -30, 0}, v]],
Text[Style["w", Large, Bold, Red], Offset[{-50, -30, 0}, w]],
Arrow[{orig, (u)}],Arrow[{orig, (v)}],Arrow[{orig, (w)}],o},
Axes -> True,AxesOrigin -> Automatic]
On my screen appears the following warning me stating the following: Too many arguments given
If I eliminate the error, my result does not appear. but if I disregard, it's OK.