We show that the following two-dimensional system of difference equations:where (a n ) n∈N 0 , (b n ) n∈N 0 , (c n ) n∈N 0 , and (d n ) n∈N 0 are periodic sequences, is solvable, considerably extending some results in the literature. In the case when all these four sequences are periodic with period 2 or with period 3, we present closed-form formulas for the general solutions to the corresponding systems of difference equations. Some comments regarding theoretical and practical solvability of the system, connected to the value of the period of the sequences, aregiven.
KEYWORDSclosed-form formula, solvable system, system of difference equations, system with periodic coefficients MSC CLASSIFICATIONwhere t 1 and t 2 are the zeros of t 2 + t + (in this case is t 1 ≠ t 2 ).Math Meth Appl Sci. 2019;42:6757-6774. wileyonlinelibrary.com/journal/mma