How do i figure this out

What is the rescursive formula for this geometric sequence? 7, -14, 28, -56

Which best describes the strength of the correlation, and what is true about the causation between the variables? it is a weak negative correlation, and it is not likely causal. it is a weak negative correlation, and it is likely causal. it is a strong negative correlation, and it is not likely causal. it is a strong negative correlation, and it is likely causal.

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station.he knows that the state tax is 5.5. how much change will he receive from a $5 bill?