54 ∠M, ∠N-?

In a cyclic quadrilateral, opposite angles are supplementary. Therefore, ∠M + ∠E = 180° and ∠N + ∠K = 180°. Given ∠E = 75° and ∠K = 53°, we have ∠M = 180° - 75° = 105° and ∠N = 180° - 53° = 127°.