Answer:
See the attachment.
Step-by-step explanation:
In each case, the variable term is 54x, so what makes it be one answer or another is the value of the constant term. The various expressions have one of these constants: +18, -18, or +6.
The two expressions with minus signs go in the "-18" bin.
The two expressions with either +6 or 3(__+2) will go into the "+6" bin.
The remaining two expressions go into the "+18" bin.
