Correct option is A
Given:
Two equations:
And m and n are not coprime, i.e., they have a common factor greater than 1.
Formula:
The number of common roots = number of solutions to xd - 1 = 0, where d = GCD of m and n
Solution:
The roots of are the m-th roots of unity (complex numbers on the unit circle spaced evenly).
Similarly, has n-th roots of unity.
If m and n are not coprime, then GCD(m, n) = d > 1
Therefore, both equations have all the d-th roots of unity in common.
This means the number of common roots is more than one — exactly d in number.
Final Answer:
The possible number of common roots is more than one