Question

x = (type an integer or a fraction. do not include the degree symbol in your answer.)

Explanation:

Step1: Identify angle - relationship

The two angles are vertical angles, so they are equal.

Step2: Set up equation

Set \(3x + 9=123\).

Step3: Solve for \(x\)

Subtract 9 from both sides: \(3x=123 - 9=114\). Then divide both sides by 3: \(x=\frac{114}{3}=38\).

Answer:

38