Respuesta :

17982

Answer:

  1. (x+2) (x-2)=[tex]x^{2}[/tex]-4

(n+m) (n-m)=[tex]n^{2} -m^{2}[/tex]

  • (r+9) ( r-9)=[tex]r^{2}[/tex]-81

Step-by-step explanation: