This thesis discusses the solution of a dual fully fuzzy linear system with fuzzy trapezoidal numbers for positive fuzzy number solutions and negative fuzzy numbers. The general form of the dual fully fuzzy linear equation system is ˜ A⊗ ˜x⊕˜b = ˜ C ⊗ ˜x⊕ ˜ d. The general form of the fully fully fuzzy dual equation system is transformed into the form of ˜ A⊗˜x = ˜ C ⊗˜x⊕…