Answer
a) 3
b) infinitely many
c) yes
Work Step by Step
a) The three vectors $v_1$, $v_2$, and $v_3$ are in {$v_1,v_2,v_3$}
b) Because Col A contains all possible linear combinations of $v_1$, $v_2$, and $v_3$, there are an infinite number of vectors in Col A.
c) $\begin{bmatrix}
2&-3&-4&6\\
-8&8&6&-10\\
6&-7&-7&11\\
\end{bmatrix}
$~$\begin{bmatrix}
1&0&\frac{7}{4}&\frac{-9}{4}\\
0&1&\frac{5}{2}&\frac{-7}{2}\\
0&0&0&0\\
\end{bmatrix}
$ Because the system of equations is consistent, p is in Col A.
