[ Eq(x9, 1/2*(k2 - (x2 + x3 + x4 + x5 + x6))),
  Eq(5670*k3*x1 + 2835*k3*x2 + 2835*k3*x3 + 2835*k3*x4 + 2835*k3*x5 + 2835*k3*x6, k3*k25),
  Eq(1*k3*x6 + 1*k3*x7, k3*k26) ]