### Linear dependence of vectors

Given two vectors $\vec{V_1}= 6\hat{x}+4\hat{y}+2\hat{z}$ and $\vec{V_2}= 10\hat{x}-5\hat{y}+3\hat{z}$:
Find $\vec{V_3}$ such that  $\vec{V_1}+\vec{V_2}+\vec{V_3}=0$.
Find $\vec{V_4}$ such that  $\vec{V_1}-\vec{V_2}+\vec{V_4}=0$.