A good answer might be:

It is probably easiest NOT to re-arrange the expression, but to do the vector addition first:

( -2, 1, 2)T  ·  ( (3, -1, 4)T + ( -2, 1, -2)T )   =   ( -2, 1, 2)T  ·  (1, 0, 2)T

  =   -2*1 + 1*0 + 2*2   =   -2 + 4   =   2


Practice with Distribution

Other times it is easiest to re-arrange the expression.

QUESTION 19:

What is: ( -2, 0, 2)T · ( (1, -1, 1)T + ( 3, 1, 4)T )