Question

Simply the radical expression

Answer 1

\[\sqrt{9b ^{2}}\]

Answer 2

\(\sqrt{9}\sqrt{b^{2}}\) -- Now what?

Answer 3

Um... is it\[\sqrt{9} = \sqrt{3^{2}}\sqrt{b ^{2}}\]

Answer 4

\(\sqrt{9} = \sqrt{3^{2}} = 3\)

You do the other piece, assuming b > 0.

Answer 5

Where did you get 3 from? and am I supposed to have an exact number in mind?

Answer 6

It's a matter of finding perfect squares. You should simply be familiar with some of them.

\(2^{2} = 4\)
\(3^{2} = 9\)
\(4^{2} = 16\)
\(5^{2} = 25\)

For example.

Answer 7

But how am i supposed to know which one ro plug in? Does it matter?

Answer 8

Plug in? Try not ever to use that term. It doesn't mean anything.

You substitute the one that works. You have a square root. You are looking for squares. If you have a cube root, you look for cubes.

If you have 9 and you need perfect squares, would you replace the \(9\) with \(4^{2}\)? I hope not. \(4^{2} = 16 \ne 9\). The ONLY Perfect Square substitution for \(9\) is \(3^{2}\)