Your last equation has
Note the negative sign, and keep on going...
The question reads: "For the matrix A below, find a spanning set for its Nullspace.
So... I want to solve for such that Ax = 0.
I row reduce; r2 -> r2-2r1, r3->r3-3r1
So we can say , , , .
So the Nullspace is spanned by
Should Ax not then be zero?
I'm obviously wrong somewhere... but I can't spot where...