hello
simply write the mathematical equations given in the task description and solve it like this :
% equations are
% 1/ a + b = 300
% 2/ maximise P = a*b
a = 1:300;
b = 300-a;
P = a.*b; % can be rewritten as P = a.*(300-a) which is the equation of a parabola (as can be seen on the plot)
[Pmax,ind] = max(P); % find max value of P and corresponding value for a and b
a_max = a(ind);
b_max = 300-a_max;
plot(a,P)
