<s>[INST] Computing the span 
Compute the span of $\begin{bmatrix} 4\\2\\10 \end{bmatrix}$ and $\begin{bmatrix} 6\\3\\15 \end{bmatrix}$

I just don't even understand what "Compute the span" is even asking me. Can anyone give me a similar example so I can mimic it?
 [/INST] Hint $$\begin{bmatrix} 4\\2\\10 \end{bmatrix}  = \frac{2}{3}\begin{bmatrix} 6\\3\\15 \end{bmatrix}$$
EDIT: Since $\begin{bmatrix} 4\\2\\10 \end{bmatrix} and\begin{bmatrix} 6\\3\\15 \end{bmatrix}$ are linearly dependent, by the definition of span:
For all $\lambda$, $\mu \in R$
The span of these vector is  $\lambda\begin{bmatrix} 4\\2\\10 \end{bmatrix}+ \mu \begin{bmatrix} 6\\3\\15 \end{bmatrix}$ = $\lambda\begin{bmatrix} 4\\2\\10 \end{bmatrix}+ \frac{2\mu}{3} \begin{bmatrix} 4\\2\\10 \end{bmatrix}$ = $(\lambda+ \frac{2\mu}{3} )\begin{bmatrix} 4\\2\\10 \end{bmatrix}$
Let U = $(\lambda+ \frac{2\mu}{3} ) \in R$ so the span {U$\times\begin{bmatrix} 4\\2\\10 \end{bmatrix}$}
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