First covert them to fractions with the same denominator so you can compare them (9/12 and 4/12), then subtract the numerators, and not the denominators (9/12-4/12), then whatever you get is the answer (5/12). If you can, simplify.
-5.25 to the nearest tenth is -5.3.
The cost increases 10 times each occupant. 35 is the initial cost.
