What are the 5 exponent rules on GRE that everyone must remember?

 In order to solve any question involving exponents you must remember the 5 basic rules of exponents. Remember them? If not we will help you jog your memory:

Exponent Multiplication Rule:
Exponent Division Rule:
Raising power to power Rule:
Common Exponent Multiplication
Common Exponent Division

Exponent rules are useful for solving any test problem that involves power. Here is a quick example:

Example:

What is the value of  if  ?

A) 1

B) 2

C) 3

D) 4

E) 5

Solution:

Step 1: The bases on both sides are not equal. However we know that ,

Therefore 

Step 2: Our equation can now be written as . Since the bases are equal, we can equate the exponents and solve the linear equation:

  

B is the correct answer.