from IPython.display import display
from sympy import *
init_printing()

var('S1 W1 W2 S3 W3')

mbal = [Eq(0, S1 - S3),
        Eq(0, W1 + W2 - W3 )]

comp = [Eq(S1, 0.77*(S1 + W1)),
        Eq(S3, 0.186*(S3 + W3))]

prod = [Eq(S3 + W3, 200)]

eqns = mbal + comp + prod

for eq in eqns:
    display(eq)


soln = solve(eqns)
soln

for (k,v) in soln.items():
    print "{:s} = {:6.2f} kg/day".format(k,float(v))