vector addition

klm

vector A= (2,-1,1)
vec. B = ( 3, 0, 5)
vec. C = (1,4,-2)
what is 2A + 3(B+C)

this is what i did:
2A = 2(2,-1,1) = (4,-2, 2)

(B+C) = (4,4,3) x 3 = (12,12, 9)

2A + 3(B+C) = (16,10,11)

is this the correct way to think and do this problem?

bel

Yes, you just add up the components because all vectors are the sum of their components; and of course, a scalar times a vector is just a vector of scaled up magnitude in the direction of the original vector.

klm

okay thank you! and is it all right to multiply like that? or is there some other rule for multiplying vectors?

bel

It is all right, because that is just a case of a scalar multiplying a vector.

klm

ok! thank you very much!