Linearly Dependent Sets and Linear Combinations (Proof Verification)

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I'm practicing my proof-writing and was hoping you could let me know if this proof looks good. I would like to know if the proof is incorrect, if there are parts that are overly wordy/complicated, or if I'm missing some element of a proof that is helpful to see, if not strictly necessary.

The Prompt (from here):

for n > 1, (v1, ..., vn) is a linear dependent set if and only if one of the vector in the set vi is a linear combination of the other n − 1 vectors.

My Proof:

Suppose (v1,...,vn) is a linearly dependent set. Then $\sum_{i=1}^n$ tivi = 0 for some nonzero t ∈ Rn. Let vk be a vector s.t. tk != 0. Then:

$\sum_{i=1}^n$ tivi = 0

$\sum_{i=1}^{k-1}$ tivi + tkvk + $\sum_{i=k+1}^n$ tivi = 0

tkvk = -$\sum_{i=1}^{k-1}$ tivi - $\sum_{i=k+1}^n$ tivi

vk = -($\sum_{i=1}^{k-1}$ tivi + $\sum_{i=k+1}^n$ tivi) / tk

Thus vk can be written as a linear combination of the other n-1 vectors (since tk != 0).

Now suppose one of the vectors in the set vi, denoted vk, is a linear combination of the other n-1 vectors, so:

vk = $\sum_{i=1}^{k-1}$ sivi + $\sum_{i=k+1}^n$ sivi

for some s ∈ Rn, where sk = 0. Then if we define t ∈ Rn s.t. ti = si for all values except tk, which equals -1, then:

$\sum_{i=1}^n$ tivi =

$\sum_{i=1}^{k-1}$ sivi + (-1)vk + $\sum_{i=k+1}^n$ sivi =

$\sum_{i=1}^{k-1}$ sivi + $\sum_{i=k+1}^n$ sivi - ($\sum_{i=1}^{k-1}$ sivi + $\sum_{i=k+1}^n$ sivi) = 0

So $\sum_{i=1}^n$ tivi = 0 when t != 0, so the set is linearly dependent.