Help give explanation too pleaseee!

Solve the formula ax+ by = c for x.

If the tip varies directly with the number of guest which equation represents between the tip,t, and the number of guest,g?

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