Semnan University International Journal of Nonlinear Analysis and Applications 2008-6822 11 Special Issue 2020 11 01 Two Efficient Methods For Solving Non-linear Fourth-Order PDEs 543 546 4751 10.22075/ijnaa.2020.4751 EN Huda Omran Altaie University of Baghdad, Department of Mathematics College of Education For Pure Sciences, Ibn Al-Haitham, Iraq Journal Article 2020 02 15 This paper studies a novel technique based on the use of two effective methods like modified Laplace- variational method (MLVIM) and a new Variational method (MVIM)to solve PDEs with variable coefficients. The current modification for the (MLVIM) is based on coupling of the Variational method (VIM) and Laplace- method (LT). In our proposal there is no need to calculate Lagrange multiplier. We applied Laplace method to the problem .Furthermore, the nonlinear terms for this problem is solved using homotopy method (HPM). Some examples are taken to compare results between two methods and to verify the reliability of our present methods. https://ijnaa.semnan.ac.ir/article_4751_83a75debb4960158a518c0e7b3d0a79c.pdf