Description: Learn how to rewrite expressions with negative exponents as fractions with positive exponents. Created by Sal Khan. We already know that 2 to the fourth power can be viewed as starting with a 1 and then multiplying it by 2 four times. One way of viewing it is this is telling us how many times are we going to multiply 2 times negative 1? But here we're going to multiply negative 4 times.*Teacher Advisor is 100% free.