Help please I’ve been looking online for help but couldn’t find any.

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Calculate the total payback for a $3,500 loan at 8% annual interest with monthly payments for two years. show all of your steps. use the formula, m = pm(1 + m)^na/(1 + m)^na - 1, as needed.

Ineed to know how to write question one in mathematical terms