Backlund transformation of the Geng-Xue system

We construct a Backlund transformation for the Geng-Xue system with the help of reciprocal and gauge transformations. Furthermore, we derive N-Backlund transformation for the Geng-Xue system resorting to Bianchi's permutability. As an application, we obtain some exact solutions of the Geng-Xue system including multi-kink, bell-shaped soliton. Finally, we discuss Backlund transformations for the Degasperis-Procesi and the Novikov equations, which are two reductions of the Geng-Xue system.