Question Video: Evaluating Algebraic Expressions with Negative Exponents Mathematics • Second Year of Preparatory School

Video Transcript

If 𝑥 equals nine and 𝑦 equals negative one, what is 𝑥 to the 𝑦 power?

In this case, we have a base of 𝑥 and a power of 𝑦. So we substitute nine for the base and negative one for the exponent. And then we need to consider our exponent rules that tell us 𝑥 to the negative 𝑎 power will be equal to one over 𝑥 to the 𝑎 power. And that means nine to the negative one power is equal to one over nine to the positive one power. Nine to the first power equals nine, which makes nine to the negative one power equal to one-ninth.