Four whole numbers have been rounded to the nearest 10. The sum of the 4 rounded numbers 90. What is the maximum sum of the 4 original numbers ?

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.