Pls help me out thank you :)

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Nicole purchased a container of cashews that weighs 5 kilograms. zion purchased a container of cashews that weighs 4,900 grams. how many more grams of cashews did nicole purchase?

What is the y-intercept of the line with the equation 3x + 4y = 12?