Linearly independent or dependent - how to show?

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Let $a$, $b$ and $c$ be a system of non-zero, non-coplanar vectors. Find a relation between the vectors $f$, $g$, $h$, $j$ given by:

$$f=a+3b+4c$$

$$g=a-2b+3c$$

$$h=a+5b-2c$$

$$j=6a+14b+4c$$

How can we show this?

My attempt:

Let's assume that they are linearly independent.

$$αf+βg+γh+λj=0 -eq(1)$$

Where each of the scalars is equal to zero $α = β = γ = λ =0$.

Substituting $f$, $g$, $h$, $j$ into (1) we get:

$$α + β + γ + 6λ=0$$ $$3α -2β + 5γ + 14λ=0$$ $$4α + 3β - 2γ + 4λ=0$$

Using this result, how do I prove that at least one of these scalars is zero or at least one of them is non-zero?

Here is an example way the textbook solves this: Finding the whether vectors are linearly independent or dependent