Respuesta :

ktreyb
Since the angles are supplementary, together they add up to 180. 

10x + 70 = 180
10x = 180 - 70
10x = 110
x = 110 / 10
x = 11

The value of x = 11, your second option. 
11: Supplementary means equal to 180°. 180= 10x-70. 110=10x. x=11.