Head First Algebra

Appendix A. Leftovers: The Top Five Things (we didn’t cover)

Note

Yes, just five. You’ve learned so much already...

You’ve learned a lot in this book, but Algebra has even more to offer. Don’t worry, we’re almost done! Before we go, there are just a few gaps we want to fill in. Then you’ll be onto Algebra 2, and that’s a whole additional book...

#1 Negative Exponents

We touched on them in Chapter 3, but as a quick refresher, here’s what a negative exponent looks like:

Combine that rule with multiplying exponential terms, and you can divide exponential terms too, like this:

What’s going on here? It’s really a matter of cancelling things out... here’s a simple example, where you can see the cancelling in action:

A negative exponent means that you divide one by the exponential term, with its exponent stripped of its negative sign. Negative exponents are a great way to get rid of fractions. Any fraction can be rewritten as a negative exponent, and you can work with it the same way you would work with any other exponent.

Negative exponents mean you can get rid of fractions.

Working with negative exponents ...