Solution: if d/dt(q1) = k12(q2) - k21(q1) and d/dt(q2) = k21(q1) - k12(q2), then where c1,c2, c3, & c4 and d1, d2, d3, & d4 = f(k12, k21) and the initial conditions. For a detailed example click here B.3-b
where c1,c2, c3, & c4 and d1, d2, d3, & d4 = f(k12, k21) and the initial conditions.
For a detailed example click here
B.3-b