1. choose the equation you can use to solve the following problem. each cupcake costs $4.00. how many cupcakes, x, are purchased if the total cost is $36.00? (1 point) 2. choose the equations you can use to solve the following problem. sam is 3 years younger than marco. marco is 15 years old. how old is sam? let x represent sam's age, in years. (2 points) 3. the equation below represents how many hours, x, it will take to travel 210 miles at an average speed of 60 miles per hour. how long will it take? 60x210