I think this is more of an opinion question. What someone could solve mentally may not be the same as someone else's.If it were my worksheet, I'd circle all of them but it may be different for you.
At your level, I'd probably circle:
54 - 10
93 - 20
and 39 - 2
Answer:
4 + 12 + 36 + ...
Step-by-step explanation:
4, 12, 36, ... is a geometric sequence, it has a common ratio of 
When we add the terms of a geometric sequence we get a geometric series.
4+12+36+ ... is a geometric series, it has a common ratio of 
4 + 12 + 20 + ... is not a geometric series because it has no common ratio

The second choice is correct
? = 30 because your number is increasing by -8 how to figure it out is by taking 14 - 6 = 8
Answer:
Written out the equation would look like f(x) = 55(1.06)^x
The graph would look something like the attached picture. (It intercepts with the y-axis at 55).