{ diff(x2, t) = ((-1)*k28*k11*k34*x2/(k12 + x2) + 1*k28*k9*x3*(k30 - x2)/(k10 + k30 - x2))/k28,
  diff(x3, t) = (1*k28*(k5*(k30 - x2) + k6*x2)*x4 + (-1)*k28*(k7*x6 + k8*(k31 - x6))*x3 + 1*k28*k4*x8*x7 + (-1)*k28*(k2*(k33 - x11) + k3*x11)*x3)/k28,
  diff(x4, t) = ((-1)*k28*(k5*(k30 - x2) + k6*x2)*x4 + 1*k28*(k7*x6 + k8*(k31 - x6))*x3 + (-1)*k28*(k2*(k33 - x11) + k3*x11)*x4)/k28,
  diff(x6, t) = ((-1)*k28*k19*k34*x6/(k20 + x6) + 1*k28*k17*x3*(k31 - x6)/(k18 + k31 - x6))/k28,
  diff(x7, t) = ((-1)*k28*k4*x8*x7 + 1*k28*k1 + (-1)*k28*(k2*(k33 - x11) + k3*x11)*x7)/k28,
  diff(x10, t) = ((-1)*k28*k23*k34*x10/(k24 + x10) + 1*k28*k21*x3*(k32 - x10)/(k22 + k32 - x10))/k28,
  diff(x11, t) = ((-1)*k28*k15*k34*x11/(k16 + x11) + 1*k28*k13*x10*(k33 - x11)/(k14 + k33 - x11))/k28,
  diff(x12, t) = 0,
  diff(x13, t) = 0,
  diff(x14, t) = 0,
  diff(x15, t) = 0,
  diff(x16, t) = 0,
  diff(x17, t) = 0 }