The reason we didn’t write the answer choices as powers of 2 was that we started the problem using regular numbers, and we should end up with an answer written in the same form. Because our dividend and our divisor are both powers of 2 (128 = 27, 16 = 24) we can use the formula
(bm)/(bn) = b(m − n)
as a short cut in the division.
Mainly we want to remind you that expressions of the form bn are simply a convenient way of writing certain numbers - that is, numbers that can be formed by using a particular base number as a factor a particular number of times.
