Answer:
50°
Step-by-step explanation:
These 2 angles are vertically opposite, meaning they equal each other.
This gives the equation 9x-4=7x+8.
Subtracting 7x from both sides gives 2x-4=8.
From there, you want to add 4 to both sides, leaving 2x=12.
In order to isolate the x, divide both sides by 2. This creates a final result of x=6.
We want to find the angle given by 8+7x. Since we know x, we can sub it with its value (6). This makes the equation 8+7×6.
We can then solve this to 8+42, and even further to 50°.
**This content involves transversals and solving algebraic equations, which you may wish to revise. I'm always happy to help!