Given two square matrix $A$ and $B$ that $\det(A)=0$ and $\det(B) \neq 0$. Is it possibly that $\det(A+B)=0$ ?
I have tried numerically, it seems that this is impossible. However I don't know how to prove it because there is no relation between $\det(A+B)=0$ and $\det(A)$, $\det(B)$.
$$ \begin{bmatrix} 1&1\\ 1&1 \end{bmatrix} = \begin{bmatrix} 1&0\\ 0&0 \end{bmatrix} + \begin{bmatrix} 0&1\\ 1&1 \end{bmatrix} $$