To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{3}{9} \) x \( \frac{3}{6} \) = \( \frac{3 x 3}{9 x 6} \) = \( \frac{9}{54} \) = \(\frac{1}{6}\)

Use PEMDAS (Parentheses, Exponents, Multipy/Divide, Add/Subtract):

3 + (5 + 3) ÷ 4 x 4 - 4²
P: 3 + (8) ÷ 4 x 4 - 4²
E: 3 + 8 ÷ 4 x 4 - 16
MD: 3 + \( \frac{8}{4} \) x 4 - 16
MD: 3 + \( \frac{32}{4} \) - 16
AS: \( \frac{12}{4} \) + \( \frac{32}{4} \) - 16
AS: \( \frac{44}{4} \) - 16
AS: \( \frac{44 - 64}{4} \)
\( \frac{-20}{4} \)
-5

In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 12 workers at the company now and that's enough to staff 3 crews so there are \( \frac{12}{3} \) = 4 workers on a crew. 8 crews are needed for the busy season which, at 4 workers per crew, means that the roofing company will need 8 x 4 = 32 total workers to staff the crews during the busy season. The company already employs 12 workers so they need to add 32 - 12 = 20 new staff for the busy season.

To simplify a radical, factor out the perfect squares:

\( \sqrt{125} \)
\( \sqrt{25 \times 5} \)
\( \sqrt{5^2 \times 5} \)
5\( \sqrt{5} \)

To add these radicals together their radicands must be the same:

8\( \sqrt{27} \) + 3\( \sqrt{3} \)
8\( \sqrt{9 \times 3} \) + 3\( \sqrt{3} \)
8\( \sqrt{3^2 \times 3} \) + 3\( \sqrt{3} \)
(8)(3)\( \sqrt{3} \) + 3\( \sqrt{3} \)
24\( \sqrt{3} \) + 3\( \sqrt{3} \)

Now that the radicands are identical, you can add them together: