This question seems to me to be an exercise in applying the rule for a difference of squares in order to rewrite the difference of two relatively large numbers as the "simpler" product of other integers.
Answer:

Step-by-step explanation:
Consider an element 
We know that 
Here, m and n are exponents and a is a base. Exponent refers to the no. of times a term is multiplied by itself. Another word for exponents is powers.
Other Properties of exponents:

Here, we are required to divide
by
.
Consider 
We will solve
separately.
Here,

So, 
Answer:
a=
or 
Step-by-step explanation:
Equate the equation to zero
-9a+2=0
-5a-4a+2=0
5a(2a-1)-2(2a-1)=0
Write out the factors
(5a-2)(2a-1)=0
Then equate each factor to zero
5a-2=0 OR 2a-1=0
5a=2 OR 2a=1
a=
OR a= 
a=
or 