en تخصصي Special پژوهشي Research paper <p>This paper deal with the solutions of the systems of difference equations $$x_{n+1}=frac{y_{n-3}y_nx_{n-2}}{y_{n-3}x_{n-2}pm y_{n-3}y_n pm y_nx_{n-2}}, ,y_{n+1}=frac{y_{n-2}x_{n-1}}{ 2y_{n-2}pm x_{n-1}},,nin mathbb{N}_{0},$$ where $mathbb{N}_{0}=mathbb{N}cup left{0right}$, and initial values $x_{-2},, x_{-1},,x_{0},,y_{-3},,y_{-2},,y_{-1},,y_{0}$ are non-zero real numbers.</p> System of difference equations, Form of the solutions, Periodicity. 73 86 http://ijmsi.ir/browse.php?a_code=A-10-634-1&slc_lang=en&sid=1 N. Touafek nouressadat_touafek@yahoo.com 10031947532846002304 10031947532846002304 Yes Jijel University