[填空题]
Consider the lines x39pdge 5wt)p vow((yxzh46tkge7 6tL_{1} and L_{2} defined by
$L_{1}: \mathbf{r}=\left(\begin{array}{c}
-6 \\
10 \\
c
\end{array}\right)+\lambda\left(\begin{array}{c}
3 \\
-3 \\
1
\end{array}\right) \text { and } L_{2}:-\frac{x}{2}=y-1=\frac{z-13}{3}$
where $\lambda \in \mathbb{R}$ and c is a constant. Given that the lines intersect at a point A ,
1. find the value of c ;
2. determine the coordinates of A . (a,b,c) a = b = c =
