Originally Posted by

**turbozz** Let A be an n × m matrix. Prove that if b is a non-zero vector in the nullspace of A transposed, then the systemof linear equations Ax = b has no solution.

So I'm not exactly sure how to go about this.

I know rank(A) = rank(A transposed)

which implies dim(col(A))=dim(col(A transposed))

And for the system to be consistent b must belong to the col(A), which implies rank(A) = n.

But wouldn't the rank(A transposed) = m for the system A(transposed) b = 0 to be consistent which implies rank(A) = m.

But then Ax=b would have no solution right?