Question

Given V={(a,b,c)| ∈R, c=a+b-1}. Is V subspace from R^3?

Answer 1

what are the things you need to check to verify that this is a subspace?

Answer 2

axioma- tization of geometry I guess

Answer 3

no, you have to show that V is closed under addition and scalar multiplication
do you know what that means?

Answer 4

then I have to check the addition and scalar multiplication by the definition?

Answer 5

...and make sure that they are still in V
why don't you see what you get when you multiply any vector in V like (x,y,x+y-1) by a scalar c ?

Answer 6

okay, i'll try, thank you