we know that
4 1/2 gallons-------> (4+2+1)/2-----> 9/2 gallons
1 wall in the house will need --------> 3/4 of a gallon of paint
X wall-----------------------------------> 9/2 gallons
x=(9/2)/(3/4)----> 9*4/2*3-----> 36/6----> 6 walls
the answer is
6 walls
