Adjacent angles are like two angles in a triangle. notice that each angle in a triangle shares a side of the triangle and also is next to both of the other triangle's angles. Adjacent means next to.
vertical angles form an X where the angle parts are joined where the two lines cross...i.e. their...

While I haven't heard that phrase "six moves long" I would guess that the teacher means answer with six steps to get the answer.

Think of the number line as a one block street with the zero a person who lives in the middle of the block. Call him Zero. Then think of negative numbers as being addresses of neighbors equally spaced to the left of this person and positive numbers being
addresses of neighbors equally spaced...

Let the number of Ben's stamps = X since the problem gives us that directly. Then since the problem gives the number of stamps for Andrew and Carl in term's of Ben's stamps we need to write equations using X which is the number of Ben's stamps.
For Andrew it says he has 86 more stamps than Ben...