Answer:
40°
Step-by-step explanation:
[tex]\cos (x-10\degree )= \frac{ \sqrt{3} }{2} \\ \\ \cos (x-10\degree )=\cos 30\degree \\ \\ x-10\degree = 30\degree \\ \\ x = 30\degree + 10\degree \\ \\ x = 40\degree[/tex]
