Parallel lines are a pair of lines that never touch each other. This means that their gradient must be equal in order to not intersect each other.
Examples of parallel lines:
These two lines above are parallel as they have the same gradient.
To prove this, use the equation below: (like, write the exact equation down to prove)
I have no idea why, but in the exam, you are required to show that the two lines are parallel to each other. That’s why I have put the equation above.
Other schools/classes might have a different way of proving that. Since this is an internal exam, follow your school’s way of proving so.
(my school used that equation written above)