Consider the Transitive Property of Parallel Lines.
See solution.
Practice makes perfect
Let's first draw line l and MN.
A translation of MN to the left of 2 units can be described as
(x,y)→ (x-2,y);
Since translation is a rigid motion it preserves length and angle measures meaning they will be parallel lines.
According to the Transitive Property of Parallel Lines, if two lines are parallel to the same line, then they are parallel to each other. Therefore since MN ∥ l and MN ∥ M'N' it must be that
M'N' ∥ l
