Solution - Simplification or other simple results

Step  1  :

Trying to factor as a Difference of Squares :

 1.1      Factoring:  c²²-d²² 

Theory : A difference of two perfect squares,  A² - B²  can be factored into  (A+B) • (A-B)

Proof :  (A+B) • (A-B) =
         A² - AB + BA - B² =
         A² - AB + AB - B² =
         A² - B²

Note :  AB = BA is the commutative property of multiplication.

Note :  - AB + AB equals zero and is therefore eliminated from the expression.

Check :  c²²  is the square of  c¹¹ 

Check :  d²²  is the square of  d¹¹ 

Factorization is :       (c¹¹ + d¹¹)  •  (c¹¹ - d¹¹) 

Final result :

  (c11 + d11) • (c11 - d11)