2019-12-142019-12-142015Cited References in Web of Science Core Collection: 350170-4214https://doi.org/10.1002/mma.3277https://cutt.ly/ve6IlfgAccession Number: WOS:000362588800010In this paper, a shifted Jacobi-Gauss collocation spectral algorithm is developed for solving numerically systems of high-order linear retarded and advanced differential-difference equations with variable coefficients subject to mixed initial conditions. The spatial collocation approximation is based upon the use of shifted Jacobi-Gauss interpolation nodes as collocation nodes. The system of differential-difference equations is reduced to a system of algebraic equations in the unknown expansion coefficients of the sought-for spectral approximations. The convergence is discussed graphically. The proposed method has an exponential convergence rate. The validity and effectiveness of the method are demonstrated by solving several numerical examples. Numerical examples are presented in the form of tables and graphs to make comparisons with the results obtained by other methods and with the exact solutions more easier. Copyright (C) 2015 John Wiley & Sons, Ltd.enUniversity for system of differential-difference equationscollocation methodJacobi-Gauss quadratureshifted Jacobi polynomialsArticlehttps://doi.org/10.1002/mma.3277