1. Why does Theorem G have the title it does?
  2. Why is Theorem RMRT so surprising ?
  3. Row-reduce the matrix $A$ to reduced row-echelon form. Without any further computations, compute the dimensions of the four subspaces, (a) $\nsp{A}$, (b) $\csp{A}$, (c) $\rsp{A}$ and (d) $\lns{A}$. \begin{equation*} A= \begin{bmatrix} 1 & -1 & 2 & 8 & 5 \\ 1 & 1 & 1 & 4 & -1 \\ 0 & 2 & -3 & -8 & -6 \\ 2 & 0 & 1 & 8 & 4 \end{bmatrix} \end{equation*}