. 27 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2019, 3 (1): 27-33 ReseaRch aRticle Cooperating Newton’s Method with Series Solution Method for Solving System of Linear Mixed Volterra-Fredholm Integral Equation of the Second Kind Talaat I. Hasan* Department of Mathematics, College of Basic Education, Salahaddin University, Erbil, Iraq ABSTRACT In this paper, for the 1st time, we use Newton’s method with series solution method (SSM) for solving system of linear mixed Volterra- Fredholm integral equations of the second kind (SLMVFIE-2). In this work, we use a new technique for studying the numerical solutions for SLMVFIE-2 which is Newton’s method with SSM, first solving this system using SSM and after that cooperation Newton’s method with SSM, suggesting an algorithm for the technique. The new results are achieved and some new theorems have proved for convergence of the method, several numerical examples are tested for illustrating the usefulness of the technique; the numerical results are obtained and compared with the exact solution, computing the least square error, and running times which are criterion of discussion. For programming the technique, we use general Matlab program. Keywords: Newton’s method, series solution method, system of linear mixed Volterra-Fredholm integral equations of the second kind, Taylor series INTRODUCTION Integral equations have been one of the significant and principal instruments in various areas of sciences such as applied mathematics physics, biology, and engineering. On the other hand, it has many applications in different areas of science, involving potential theory, electricity, and quantum mechanics.[1,2] In the past 20 years ago, many kinds of problems in integral equation making from various phenomena in applied mathematical physics. The mixed Volterra-Fredholm integral equations can be constructed form ordinary differential equations with changed argument,[3-5] which arising from the theory of parabolic boundary value problems. In addition, this type of problems appears in various physical and biological problems.[6,7] Recently, many kinds of integral equations constructed and reformulated; the approximating methods take an important role for finding the numerical solution for these classes of problems in integral equations. It has many advantages witnessed by the increasing frequency of the integral equations in literature and in many areas, because some problems have their mathematical representation appear directly.[8,9] Then, for the reasons, many scientists applied different techniques for finding numerical solution of integral equations, Maleknejad, in 2006, solved system of Volterra-Fredholm integral equations using computational method; Chen, in 2013, studied the approximate solution for mixed linear Volterra-Fredholm integral equation. Wazwaz, in 2011, solved Volterra integral equation of the second kind using series solution method (SSM). Young, in 2015, used Newton’s Raphson for finding the approximate solution of non-linear equations. Hassan, in 2016, found numerical solution of linear system Volterra-Fredholm integral equation. Saleh, in 2017, studied system of Volterra-Fredholm integral equation of the second type, for extending this work, the system of linear mixed Volterra-Fredholm integral equations of the second kind (SLMVFIE-2) is studying and finding the numerical result of it by cooperating the NM with SSM and using power functions u x xi m i m( ) ,= for m=0, 1, 2, 3,…q. SOME DEFINITIONS AND THEOREMS In this section, discussing some definitions and theorem, which relate to the study. Cihan University-Erbil Scientific Journal (CUESJ) Corresponding Author: Talaat I. Hasan, Department of Mathematics, College of Basic Education, Salahaddin University, Erbil, Iraq. E-mail: talhat.hassan@su.edu.krd Received: Nov 13, 2018 Accepted: Dec 24, 2018 Published: May 13, 2019 DOI: 10.24086/cuesj.v3n1y2019.pp27-33 Copyright © 2019 Talaat I. Hasan. This is an open-access article distributed under the Creative Commons Attribution License. https://creativecommons.org/licenses/by-nc-nd/4.0/ Hasan: Cooperating Newton’s Method with Series Solution Method 28 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2019, 3 (1): 27-33 Definition (1) We assume SLMVFIE-2 as follows: u x f x k x t u t dtdxi i j n ij a x ij j a b ( ) ( ) ( , ) ( )= + = ∑ ∫ ∫ 1  (1) For i=1, 2, 3,…r. Where f i (x) and k ij (x,t) are analytic functions on domain H= {(x,t), a≤t