Hi Adam, if my understanding of the problem faced here is correct then the issue is likely due to the way the equations are being interpreted when using 'equationsToMatrix'. The function solves for the coefficients in a linear system, and coeffecients can be factored.
As both 'b' and 'Cprop_bottom' are negative essentially means the same solution. One possible workaround would be to normalize/simplify the equations (using 'simplify')
Refer to the below example code using 'equationsToMatrix':
syms a1 b1 a2 b2
e1 = -2*a1 - 3*b1 == -5;
e2 = -4*a1 - 5*b1 == -7;
[A, b] = equationsToMatrix([e1, e2], [a1, b1]);
disp('Matrix A:');
disp(A);
disp('Matrix B:');
disp(b);
e1 = simplify(e1);
e2 = simplify(e2);
[A, b] = equationsToMatrix([e1, e2], [a1, b1]);
disp('Matrix A:');
disp(A);
disp('Matrix B:');
disp(b);
Additionally you can refer to the MathWorks documentation of 'equationsToMatrix' and 'simplify':
