Answer:
The solution to the question will be explained better using the image below
Concept:
The formula to calculate momentum is given below as
[tex]\begin{gathered} momentum=mass\times velocity \\ m=mv \end{gathered}[/tex]The first momentum will be
[tex]\begin{gathered} m_1=m_1v_1 \\ m_1=6\times13 \\ m_1=78kg\text{ m/s} \end{gathered}[/tex]The second momentum will be
[tex]\begin{gathered} m_2=m_2v_2 \\ m_2=14kg\times7 \\ m_2=98kg\text{ m/s} \end{gathered}[/tex]Since they are moving in different directions,
We will substract both momentums
[tex]\begin{gathered} momentum=m_1v_1-m_2v_2 \\ momentum=78-98 \\ momentum=-20kg\text{ m/s} \end{gathered}[/tex]Hence,
The momentum of a system that consists of two objects should be 20 kg m/s in the direction of the negative x-axis