Nine I believe, because fifth teen divided by five equals three
three times three equals nine.
The common difference
(-73 - -40)/(28 - 17) = -3
Term a1: -40 - (-3*(17-1)) = 8
Term a2: 8+-3=5
Term a3: 2
Term a4: -1
Term a5: -4
Do you have to use substitution?
The range is the difference between the highest and lowest values in a set of numbers. To find it, subtract the lowest number in the distribution from the highest.