How do I add three vector components together?

[physicssux]

how do i add up 3 different vector components...

i tried drawing them up in scale but had NO LUCK...some one please help.

 

[finchie_88]

If you have two vectors, let's say a = xi + yj + zk, and b (same thing, but different values of x,y and z, then, the sum of them is simple the sum of the components. The same holds true for 3 vectors.
eg. a = i+j, b = 2i +j, then a+b = 3i + 2j