Initial costs 750 and loses .28 of value each year, so still worth 1-.28=.72 of value at start of next year. 750*(.72)^n is the value after n years since for n=0, new, it is 750*.72^0=750*1=750, and after 1 year it is worth 750*.72^1=750*.72 means it lost 28% value after one year. If you with to express it as an exponential exp(..) you need to convert the .72^n into exp(log(.72)*n)=exp(-.3285*n) so you get
That's true. If the integers both have the same sign, then their product and quotient are both positive. If signs are different, then product and quotient are both negative.