Help for both 7 and 8

If f(x)= sqrt4x+9+2, which inequality can be used to find the domain of f(x)?

2/3(-6y+9x) expand each expression using the distributive property

Tony is charged $ 50 and additional $0.15 per miles for renting a car. a) represent the cost of renting a car with an equation,and the determine the cost if he drove it70 miles.b) what would be the cost of a car rental if the car was driven 250 miles? show work