Kenny has $1,400 in the bank. he earns $150 every week at his afterschool job. what is the rate of change for the scenario described?

Icould really use some with this question.

Bella want to know what the students at her school think of her show. which is the best group to survey to find this information a. go to the mall and ask all of the students she recognizes from school b. ask her viewers to call in durning an episode of the show c. get a list of students at her school from the office and use a random number generator to pick 30 of them d. get a list of students at her school from the office and pick the first 30 students on the list

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left