Choose one optimal value in gamultiobj optimization algorithm

Hi can you help me please , i want to make optimization in multi objective function as this example

 function y = simple_multiobjective(x)
   y(1) = (x+2)^2 - 10;
   y(2) = (x-2)^2 + 20;
x = -10:0.5:10;
f1 = (x+2).^2 - 10;
f2 = (x-2).^2 + 20;
FitnessFunction = @simple_multiobjective;
numberOfVariables = 1;
A = []; b = [];
Aeq = []; beq = [];
lb = -1.5;
ub = 0;
x = gamultiobj(FitnessFunction,numberOfVariables,A,b,Aeq,beq,lb,ub);

my problem is when i want to take the optimal value of x , the algorithm gives me a lot of numbers and i do not know which one is optimal number . can you help me

thank you