(1) For the $\mathbb{R}$-algebra $\mathbb{C}$, ($\mathbb{R}$ real number field, $\mathbb{C}$ complex number field) there is no quiver $Q $ such that $\mathbb{C}\cong \mathbb RQ/\mathcal{I}$ with $\mathcal{I}$ an admissible ideal of $\mathbb{R}Q$, why?
(2) Let $A$ be the $\mathbb{R}$-algebra$\left[ \begin{array}{cc} \mathbb{C} & \mathbb{C} \\ 0 & \mathbb{R} \\ \end{array} \right]$. Then $A$ is a basic $\mathbb{R}$-algebra, but there is no quiver $Q $ such that $A\cong \mathbb{R}Q/\mathcal{I}$ with $\mathcal{I}$ an admissible ideal of $\mathbb{R}Q$. why?