Solving 2 ODE's with ode45

Im trying to solve these 2 differential equations like this:

tfinal = 100;
t = linspace(0,tfinal,100);
winitial = [1 300];
[T, Ca] = ode45(@sub1,t,winitial)

plot(t,Ca)

%%%%%%%%% Subfunction
function d_dt = sub1(Ca,T)
    d_dt =  zeros(2, 1);
    d_dt(1,1) = -0.1*Ca*exp(-300/T);
    d_dt(2,1) = 1*Ca*exp(-300/T);
    
end

but i keep getting these errors. Does it have something to do with the subfunction? I was having trouble with it

Unable to perform assignment because the size of the left side is 1-by-1 and the size of the right side is 1-by-2.

Error in explicit_Eu_hw>sub1 (line 28)
    d_dt(1,1) = -0.1*Ca*exp(-300/T);

Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.

Error in ode45 (line 115)
  odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in explicit_Eu_hw (line 20)
[T, Ca] = ode45(@sub1,t,winitial)

Answer 1

[Stephan]

tfinal = 100;
tspan = [0 tfinal];
winitial = [1 300];
[t,y] = ode45(@sub1,tspan,winitial)
plot(t,y,'LineWidth',2)

%%%%%%%%%Subfunction
function d_dt = sub1(t,y)
Ca = y(1);
T=y(2);
d_dt = zeros(2, 1);
d_dt(1,1) = -0.1*Ca*exp(-300/T);
d_dt(2,1) = 1*Ca*exp(-300/T);
end