Answer:
They are parallel
Explanation:
Ignore the +3 and the +6 for this problem because both of these graphs have an equal slope!
They both have a leading coefficient of -1, which means their slopes are equal. Because of this, they are parallel.
Here is a fun fact: If two graphs have the same slope (number in front of x) and have different y-intercepts (b values/constants added/subtracted) then they are parallel.
Hope this helps!