[tex]\text{Doi vectori }\vec{v}= a\cdot \vec{i}+b\cdot \vec{j} \text{ si }\vec{u}=x\cdot \vec{i}+ y\cdot \vec{j} \text{daca si numai daca }\\
\boxed{\dfrac{a}{x}=\dfrac{b}{y}}\\
\text{In cazul de fata:}\\
\vec{u}\text{ si }\vec{v} \text{ sunt coliniari } \Leftrightarrow \dfrac{1}{5}=\dfrac{4}{20}\Leftrightarrow \dfrac{1}{5}=\dfrac{1}{5}(A)\\
\text{Deci vectorii sunt coliniari.}[/tex]
