Solution - Simplification or other simple results

Step  1  :

 1.1    Rewrite   (a-2)    as  (-1) •  (2-a) 

Multiplying Exponential Expressions :

 1.2    Multiply  (2-a)  by  (2-a) 

The rule says : To multiply exponential expressions which have the same base, add up their exponents.

In our case, the common base is  (2-a)  and the exponents are :
          1 , as  (2-a)  is the same number as  (2-a)¹ 
 and   1 , as  (2-a)  is the same number as  (2-a)¹ 
The product is therefore,  (2-a)⁽¹⁺¹⁾ = (2-a)² 

Final result :

  (2 - a)2 • -1