Respuesta :

tqiu

Answer:

x = 20

Step-by-step explanation:

For a and b to be parallel, they must both add up to 180. Therefore, we can set up an equation:

3x+6x = 180

9x = 180

x = 20

Andouhaoyu0704

Answer: X=20

Step-by-step explanation: Angle 4 and angle 5 are same side interior angles which means they are supplementary(180) and 3x+6x=180 would simplify to 9x=180 and by dividing 180/9 you get x=20.