Respuesta :

Answer:

[tex]\boxed{a = 7~~or~~a = -7}[/tex]

Step-by-step explanation:

[tex]a^2 - 49 = 0[/tex]

[tex]a^2 = 49[/tex]

[tex]a = \pm \sqrt{49}[/tex]

[tex]a = \pm 7[/tex]