Iam a factor of 50 and a multiple of 5. i am a 2-digit number greater than 10 but less than 40. what number am i ?

Carla is saving money for a trip this summer. she already has some money in her savings account and will add the same amount to her account each week. at the end of 2? weeks, carla has? $130. at the end of 8? weeks, she has? $280. write a linear function in the form y=mx+b to represent the amount of money m that carla has saved after w weeks.