[ Diff(x[1], t) = (1*k[11]*k[1] + (-1)*k[11]*k[2]*x[1] + (-1)*k[11]*k[3]*x[1]*x[2] + (-1)*k[11]*k[4]*x[1]*x[3])/k[11],
  Diff(x[2], t) = (1*k[11]*k[5]*k[3]*x[1]*x[2] + (-1)*k[11]*(k[2] + k[6])*x[2])/k[11],
  Diff(x[3], t) = (1*k[11]*k[7]*k[4]*x[1]*x[3] + (-1)*k[11]*(k[2] + k[8])*x[3])/k[11] ]