Hi everyone!

I`ve tried all the week to solve this equation but i havent found the solution. its a linear programing problem. I ve defined the variables and the function but i cant solve it con LP, the program only runs with NLP.Could you help me. Please

this is the function and constraints

[ CODE ]

$OFFSYMXREF

$OFFSYMLIST

option limrow=0;

option limcol=0;

option solprint=on;

option sysout=off;

option LP=CPLEX;

option MIP=CPLEX;

option NLP=CONOPT;

option MINLP=DICOPT;

option OPTCR=0;

$TITLE VMI

$ONTEXT

P_c=Maximize∑_(j=1)^N▒{a_j y_j-b_j y_j^2-δy_j-0.5θ_j y_j^2-[√(2y_j (H_s+H_bj )(S_s+S_bj+p_j σ_LTj L(z_j)) )+(H_s+H_bj )(z_j σ_LTj+σ_LTj L(z_j))]}

$OFFTEXT

VARIABLE F1, x;

EQUATIONS funobj, rest1, rest2, rest3;

funobj… F1 =E= (20*x)-(.003*sqr(x))-(7*x)-((0.5*.004)*sqr(x))-(sqrt(2*(9+7)*(15+10)*sqr(x)));

rest1… 2000=G=x;

rest2… x=L=4000;

rest3… x=G=0;

model problema1 /all/;

options LP = Cplex;

solve problema1 using LP maximizing F1;

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