what is the value of x??

Answer:
[tex]\displaystyle 25 = x[/tex]
Step-by-step explanation:
You are given the angle of the whole set, so set both expressions equivalent to the given angle measure:
[tex]\displaystyle 166° = 66° + [4x]° \hookrightarrow \frac{100}{4} = \frac{4x}{4} \\ \\ \boxed{25 = x}[/tex]
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