Respuesta :

Hi, I'm from Brazil :)

How about this,

(y + 30°) + y + 40° = 180°

y + y + 30° + 40° = 180°

2y + 70° = 180°

2y = 180° – 70°

2y = 110°

y = [tex] \mathsf{\dfrac{110^o}{2} } [/tex]

[tex] \boxed{\boxed{ \mathsf{y = 55^o} }}} [/tex]