Respuesta :

Step-by-step explanation:

60°+(7x-12)°+90° = 180°. (angle sum property of triangle)

(7x-12) + 150° = 180°

(7x-12) = 180° - 150°

7x-12 = 30°

7x = 30 + 12

7x = 42°

x = 42°/7

x = 6°