They are abstract "word" problems, offered for the purpose of giving the
student of high school mathematics valuable practice in the application
and manipulation of the concept of "percent".
Often, some time spent in solving practice-examples such as these can
lead to the phenomenon known as "learning", whereby the student comes
to know, understand, and possess competence in a topic where he or she
was previously ignorant and incompetent.
It is important to realize that the practice is the vital component in the process,
whereas the answers alone have no value at all.
By looking at it, I can tell the second expression is greater due to a a large postive number that's being added to it. Let's solve.
-12+6=-6-4=-10
-34-3=-37+39=2
So, -34-3+39 is greater.
For the sequence 2, 6, 18, 54, ..., the explicit formula is: an = a1 ! rn"1 = 2 ! 3n"1 , and the recursive formula is: a1 = 2, an+1 = an ! 3 . In each case, successively replacing n by 1, 2, 3, ... will yield the terms of the sequence. See the examples below.
