I need help with these

1) A delivery truck, with its fuel and driver, weighs 7500 pounds when it is empty of cargo. It is being loaded with boxes of canned goods. Each box has a total weight of 26 pounds. show an expression for the total weight of the truck when it first leaves its loading dock to make its deliveries. Define any variables you use. (Assume the number of cases will never exceed the capacity of the truck.)

2) Roberto has been playing bass 3 times as many years as his brother Felix has.

show an algebraic expression for the number of years Roberto has been playing bass. Be sure to indicate what the variable in your expression represents.

3) Citizens less than 18 years old are not allowed to vote. Define a variable and show an inequality for the ages of citizens who are not allowed to vote.