Solution

def twoChoice2(ret1,ret2,var1,var2,cov,goalVar):
    varEquation = sympy.Eq(goalVar,p1**2*var1+p2**2*var2+2*p1*p2*cov)
    totalPercent = sympy.Eq(1,p1+p2)
    dictionaries = sympy.solve((varEquation,totalPercent))
    best = [1,0,0]
    for dictionary in dictionaries:
        percent1 = dictionary[p1]
        percent2 = dictionary[p2]
        ret = percent1*ret1+percent2*ret2
        if ret>best[2]:
            best = [percent1,percent2,ret]

    print("Put "+str(best[0]*100)+"% in asset 1.")
    print("Put "+str(best[1]*100)+"% in asset 2.")
    print("Your return will be "+str(best[2]))
twoChoice2(.03,.09,.05,.07,.03,.045)

Source Code