k4*x3 - k3*k5*x1*x2 + k2*k5*x3*x4 
k1*x5 + k4*x3 - k3*k5*x1*x2 
k3*k5*x1*x2 - k4*x3 - k2*k5*x3*x4 
k1*x5 - k2*k5*x3*x4 
k2*k5*x3*x4 - k1*x5 
x4 - k9 + x5 
x1 - k10 + x3 
x2 - k11 + x3 + x5 
