Respuesta :

Answer:

x=12

Step-by-step explanation:

The three angles add to a straight line which is 180 degrees

20 + 6x-2 + 90 = 180

Combine like terms

108 + 6x = 180

Subtract 108 from each side

108+6x-108 = 180-108

6x =72

Divide each side by 6

6x/6 = 72/6

x=12