Answer:
C) 
Step-by-step explanation:
Use the Angle Addition Postulate to figure this out:

165° = (x + 15)° + (9x)°
165° = (15 + 10x)°
- 15° - 15°
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![\displaystyle \frac{150°}{10} = \frac{[10x]°}{10} \\ \\](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7B150%C2%B0%7D%7B10%7D%20%3D%20%5Cfrac%7B%5B10x%5D%C2%B0%7D%7B10%7D%20%5C%5C%20%5C%5C)
[Plug this back into the modeled expression for the
to get the angle measure of 30°]; 
I am joyous to assist you anytime.
For any point to be in the first quadrant, it must have a positive "x" value and "y" value.
If x = 1 then y = 2, a point with both x and y positive values which would be in the First Quadrant.
Answer:
x = 30
Step-by-step explanation:
1/2(x+6) = 18
Distribute
1/2 x + 3 = 18
Subtract 3 from each side
1/2x +3-3 = 18-3
1/2x = 15
Multiply each side by 2
1/2x*2 = 15*2
x = 30