Two variables that are mutually dependant

Dear Sir, I shall be very grateful to you if you help me in this regard.

clear all ; 
clc;
Demand=300;
%%...........UNITS MIN AND MAX LIMITS ...........%%
a(1,1)=100; b(1,1)=600; %bounds on variable 1
a(1,2)=100; b(1,2)=400; %bounds on variable 2
a(1,3)=50; b(1,3)=200; %bounds on variable 3
B=[0.000136 0.0000175 0.000184;0.0000175 0.000154 0.000283;0.000184 0.000283 0.000161]; %Power Loss B Coefficient Matrix %

%%================INITIAL POPULATION ============%%
x=a+(b-a).*rand(1,3);
T=x(:,1)+x(:,2)+x(:,3); %total
z=[x(:,1)./T(:,1) x(:,2)./T(:,1) x(:,3)./T(:,1)]; % Equlity constraint
p= z.*Demand;
Total= p(:,1)+p(:,2)+p(:,3);

%%.................COST FUNCTION.............%%
f1=561+ 7.92.*p(:,1)+0.00156.*(p(:,1).^2);
f2=310+ 7.85.*p(:,2)+0.00194.*(p(:,2).^2);
f3=78+ 7.97.*p(:,3)+0.00482.*(p(:,3).^2);
TC=f1+f2+f3

%%.................Power Loss.............%%
PL=bsxfun(@times,bsxfun(@times, B,p),p');
PL=sum(PL(:))

I want to calculate TC by adding PL in demand so that

p= z.*(Demand+PL).

Please tell me how I can do this. I need p to calculate PL and PL to calculate p .