Given

x1=[-1 2 3]^T x2=[3 4 2]^T x=[2 6 6]^T y=[-9 -2 5]^T

Is x Є Span(x1,x2)?

I'm not sure where to go with this. It doesn't seem as though x1 and x2 would span R^3 but I don't know if that would be relevant or not. Any help would be appreciated, thank you!