Please give me the correct answer.

What is the common difference in the following arithmetic sequence? 7,3,-1,-5

Idont get this question can someone me solve it? ** the distance light travels in one second (1 light second) is about 1.86 ×10^5 mi. saturn is about 475 light-seconds from the sun. about how many miles from the sun is saturn..my guess is 8.83* 10^7 you so much

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula c= r/1.8 - 273, what is the temperature in celcius corresponding to r degrees rankine.