Find the sum of the values of $x$ such that $\cos^{3}3x+\cos^{3}5x= 8\cos^{3}4x\cos^{3}x$, where $x$ is measured in degrees and $100 ^\circ < x < 200^\circ$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find the sum of the values of $x$ such that $\cos^{3}3x+\cos^{3}5x= 8\cos^{3}4x\cos^{3}x$, where $x$ is measured in degrees and $100 ^\circ < x < 200^\circ$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
906
Find the sum of the values of $x$ such that $\cos^{3}3x+\cos^{3}5x= 8\cos^{3}4x\cos^{3}x$, where $x$ is measured in degrees and $100 ^\circ < x < 200^\circ$.
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