Question

Simplify ^3 √-9 * ^3 √-81 using the multiplication rule. please help!

Answer 1

Explanation:

I won't take the time to explain WHY it works (you can find that elsewhere), but when the "power" of the root is the same, you can first just multiply the numbers, and THEN take the root.

Here's what it looks like:

`\sqrt[3]{-9}` ·
`\sqrt[3]{-81}` =
`\sqrt[3]{(-9)(-81)}` =
`\sqrt[3]{729}` = 9

So just remember that: whether it's square roots or cube roots or whatever-roots, as long as they're the same, you can move the multiplication operation under the root symbol. (It works for division too, but not for addition and subtraction.)