For which value of aaa is the vector v=(1,2,a)v = (1, 2, a)v=(1,2,a) in the span of u1=(1,0,1)u_1 = (1, 0, 1)u1=(1,0,1) and u2=(0,1,1)u_2 = (0, 1, 1)u2=(0,1,1)?
a=1a = 1a=1
a=2a = 2a=2
a=3a = 3a=3
a=0a = 0a=0