Please help me this is due in 30 minutes

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

Which of the following best describes the delian problem?

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula , what is the temperature in celsius corresponding to r degrees rankine? a. 9/5(c - 273) b. 9/5(c + 273) c. 5/9( c - 273) d. 5/9( c + 273)