Solution - Factoring multivariable polynomials

Step  1  :

Equation at the end of step  1  :

  (16 • ((x + y)2)) -  25 • (x - 3y)2

Step  2  :

Equation at the end of step  2  :

  16 • (x + y)2 -  25 • (x - 3y)2

Step  3  :

 3.1     Evaluate :  (x+y)2   =    x2+2xy+y2 
 3.2     Evaluate :  (x-3y)2   =    x2-6xy+9y2 

Step  4  :

Pulling out like terms :

 4.1     Pull out like factors :

   -9x² + 182xy - 209y²  =   -1 • (9x² - 182xy + 209y²) 

Trying to factor a multi variable polynomial :

 4.2    Factoring    9x² - 182xy + 209y² 

Try to factor this multi-variable trinomial using trial and error 

 Found a factorization  :  (x - 19y)•(9x - 11y)

Final result :

  (19y - x) • (9x - 11y)