The car is stationary, so
I choose an axis to be through both front wheels.
f = front b = back
This force is divided up equally between both rear tires, so the force per tire is equal to half this number.
The sum of the normal forces on the tires must equal the weight of the car:
Again, this force exerted on the front tires is divided up evenly between the two front tires, so we divide this number by two to get the force per front wheel: