Respuesta :

Steps:

[tex]Interior +interior=exterior[/tex]

but since one of the interiors are missing we will do this.

= [tex]50+X=100[/tex]

[tex]-50[/tex]            [tex]-50[/tex]

the 50 is canceled  so we are left with 100-50 which is 50 so the answer is

[tex]X=50[/tex]

Inform me if its wrong.