3rd question in less than 24 hours

I'm confused on this could anyone me and show me what i need to do to solve it.

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83

If the car had not hit the fence, how much farther would it have skidded? solve the skid-distance formula to find the extra distance that the car would have traveled if it had not hit the fence. round your answer to two decimal places. note that unit conversion is built into the skid distance formula, so no unit conversions are needed.