We mainly study the transcendental entire solutions of the differential equation f n ( z ) + P ( f ) = p 1 e α 1 z + p 2 e α 2 z , where p 1 , p 2 , α 1 and α 2 are nonzero constants satisfying α 1 ≠ α 2 and P ( f ) is a differential polynomial in f of degree n − 1 . We improve Chen and Gao’s results and partially answer a question proposed by Li (J. Math. Anal. Appl. 375 (2011), pp. 310–319).

In this paper, we study finite-order entire solutions of nonlinear differential-difference equations and solve a conjecture proposed by Chen, Gao, and Zhang when the solution is an exponential polynomial. We also find that any exponential polynomial solution of a nonlinear difference equation should have special forms.

In this paper, we find the entire solutions of two classes of nonlinear difference equations when the solution is an exponential polynomial by using the new obtained Clunie Lemma. Some examples are given to show the existence of the solutions.