Answer:
x = 15°
Step-by-step explanation:
First Identify the angle of x by subtracting 180° - 120° = 60°
Always remember when you see a straight line the line measures 180°
So the angle of x = 60° but not the value of x so use the given equation to find the value of x
3x + 15 = 60°
3x - 15 = -15°
3x = 45
x = 15°
