en Fuzzy Sets and Systems Fuzzy Sets and Systems كاربردي Applicable <span style="font-size:11pt"><span style="line-height:normal"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><i><span style="font-size:10.0pt"><span style="letter-spacing:-.25pt">In this paper, we deal with a fully fuzzy linear programming (FFLP) when the constraints are described as equality and inequality. With respect to Hadi method which is a new and a comfortable ranking method for ordering the trapezoidal fuzzy numbers, we introduce a new ranking function. We show that this function has some smooth properties when we use it for new classes of the trapezoidal fuzzy numbers which we called them k-scale trapezoidal fuzzy numbers. The k- scale trapezoidal fuzzy numbers are in fact a generalization of symmetric trapezoidal fuzzy numbers. Based on this ranking function, a new method is proposed to find the fuzzy solution for solving k-scale FFLP. Numerical examples are providing to illustrate the method.</span></span></i></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt"><span style="letter-spacing:-.15pt"></span></span></span></span></span></span><br> &nbsp; Fully fuzzy linear programming, Trapezoidal fuzzy numbers, Hadi ranking method. 159 170 http://iors.ir/journal/browse.php?a_code=A-10-6089-2&slc_lang=en&sid=1 Masomeh Gholizadeh m.gholizadehumz@gmail.com 00031947532846003149 00031947532846003149 No Department of Mathematics University of Mazandaran, Babolsar, Iran Babak Khabiri babakkhabiri.2009@shahroodut.ac.ir 00031947532846003150 00031947532846003150 No Department of Mathematics, Islamic Azad University, Jouybar Branch, Jouybar, Iran Gohar Shakouri gshakoori2@gmail.com 00031947532846003151 00031947532846003151 Yes Rahman Institute of Higher Education, Ramsar, Iran