Solution - Simplification or other simple results

Step  1  :

Trying to factor by splitting the middle term

 1.1     Factoring  x²-30x+225 

The first term is,  x²  its coefficient is  1 .
The middle term is,  -30x  its coefficient is  -30 .
The last term, "the constant", is  +225 

Step-1 : Multiply the coefficient of the first term by the constant   1 • 225 = 225 

Step-2 : Find two factors of  225  whose sum equals the coefficient of the middle term, which is   -30 .

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -15  and  -15 
                     x² - 15x - 15x - 225

Step-4 : Add up the first 2 terms, pulling out like factors :
                    x • (x-15)
              Add up the last 2 terms, pulling out common factors :
                    15 • (x-15)
Step-5 : Add up the four terms of step 4 :
                    (x-15)  •  (x-15)
             Which is the desired factorization

Multiplying Exponential Expressions :

 1.2    Multiply  (x-15)  by  (x-15) 

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

In our case, the common base is  (x-15)  and the exponents are :
          1 , as  (x-15)  is the same number as  (x-15)¹ 
 and   1 , as  (x-15)  is the same number as  (x-15)¹ 
The product is therefore,  (x-15)⁽¹⁺¹⁾ = (x-15)² 

Final result :

  (x - 15)2