{ diff(x1, t) = (1*k40*k1*x1*(1 - k2*x1) + (-1)*k40*k3*x4*x1 + (-1)*k40*k4*(x3/x1)^(2/3)/(k7 + (x3/x1)^(2/3))*x1 + 1*k40*1/10*k1*k9*x2*x1*(1 - k2*x1))/k40,
  diff(x2, t) = (1*k40*1/10*k1*x2*(1 - k9*x2) + (-1)*k40*k12*x2 + 1*k40*k10*x1/(k11 + x1)*x2*(1 - k9*x2))/k40,
  diff(x3, t) = (1*k40*k13 + (-1)*k40*k14*x3 + (-1)*k40*k15*x3*x1 + (-1)*k40*k16*x3^2 + 1*k40*k17*x4*x1 + 1*k40*k18*x5*x3/(k19*k36 + x5) + 1*k40*k20*(k37*x3 + k38*x4 + k39*x5)*x3/(k21 + k37*x3 + k38*x4 + k39*x5))/k40,
  diff(x4, t) = (1*k40*k22 + (-1)*k40*k23*x4 + (-1)*k40*k24*x1*x4 + 1*k40*k25*x5*x4/(k26*k36 + x5) + 1*k40*k27*(k37*x3 + k38*x4 + k39*x5)*x4/(k28 + k37*x3 + k38*x4 + k39*x5))/k40,
  diff(x5, t) = (1*k40*k29 + (-1)*k40*k30*x5 + (-1)*k40*k31*x5^2 + 1*k40*k32*x5*x5/(k33*k36 + x5) + 1*k40*k34*(k37*x3 + k38*x4 + k39*x5)*x5/(k35 + k37*x3 + k38*x4 + k39*x5))/k40 }