Equation I
human = eating + sleeping + working + entertaining
donkey = eating + sleeping
Then:
human = donkey +working + entertaining
So:
human – entertaining = donkey + working
In other words:
human who doesn’t entertain = working donkey

Equation II
man = eating + sleeping + earning money
donkey = eating + sleeping
Then:
man = donkey + earning money
So:
man – earning money = donkey
In other words:
man who doesn’t earn money = donkey

Equation III
woman = eating + sleeping + wasting money
donkey = eating + sleeping
Then:
woman = donkey + wasting money
So:
woman – wasting money = donkey
In other words:
woman who doesn’t waste money = donkey

Out of combination of equations II and III we get:
Man who doesn’t earn money = Women who doesn’t waste money
So,
Man earns money to not let woman become a donkey (1)
And,
Woman wastes money to not let man become a donkey(2)

Finally we have:
man + woman = donkey + earning money + donkey + wasting money
And from (1) and (2) we can make a conclusion that:
man + woman = two donkeys who live happily together