Here it is probably easiest to do the dot product first:
( -2, 0, 2)T · ( (1, -1, 1)T + ( 3, 1, 4)T )
= ( -2, 0, 2)T · (1, -1, 1)T + ( -2, 0, 2)T · ( 3, 1, 4)T = 0 + 2 = 2
You may find it useful to distribute your study time over the following topics:
Click on a term to see where it was discussed in this chapter. Remember to click on the "Back" arrow of your browser to get back to this page. The next chapter will discuss how the dot product relates to the length of a vector.