Rational numbers . Thank you !

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Guys i really need or i have to stay late up night

0if x and y vary inversely and y=6 as x=7, what is the constant of variation?