Explanation is in the file
tinyurl.com/wpazsebu
2-3=1
4-5=20
1-2=1
i think this is it i have never really been good at this but i think it could be those one
Answer:

Step-by-step explanation:
The value in 
The value in 
The value in 
In a geometric progression:
a, b, c, d...
The common ratio can be obtained using:
b/a = c/b = d/c
b/a = 112 / 64 = 1.75
c/b = 196 / 112 = 1.75
d/c = 343 / 196 = 1.75
The common ratio = 1.75
Answer:
You add it in your mind.
Step-by-step explanation: