Answer:
1. base: 5
2. base: 1.2
3. base: 

Explanation:
The basic format of an exponent and base can be written 
 in which b represents the base and n represents the exponent.
 in which b represents the base and n represents the exponent.
The exponent is the number of times that base is multiplied by itself.
The base is the number being multiplied by itself.
Using the basic format 
 you can find out the base and exponent in the given expressions. The number written in superscript is the exponent and the number it is attached to is the base.
 you can find out the base and exponent in the given expressions. The number written in superscript is the exponent and the number it is attached to is the base. 
1. 
 
 
base: 5
exponent: 12
2. 

base: 1.2
exponent: 2
3. 

base: 

exponent: 4