Answer
They are congruent
Work Step by Step
To find the length of a segment on a number line, subtract the smaller point from the bigger point.
We start with MP: $M=-3$ and $P=6$. Subtracting the smaller one from the bigger one gives $3-(-6)=3+6=9$.
For NQ, $N=3$ and $Q=12$. Subtracting the smaller one from the bigger one gives $12-3=9$
These segments are congruent because they have an equal length.