Respuesta :

[tex]\\ \sf\ast\Rrightarrow x^2-400[/tex]

[tex]\\ \sf\ast\Rrightarrow (x)^2-(20)^2[/tex]

  • a^2-b^2=(a+b)(a-b)

[tex]\\ \sf\ast\Rrightarrow (x+20)(x-20)[/tex]

aniilsah555

Step-by-step explanation:

  • x²-400
  • (x)²-(20)²

By the formula, [a²-b²=(a+b)(a-b)]

  • (x+20)(x-20)

Hence, first option is correct