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

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

Now that the radicands are identical, you can subtract them:

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{10 + 2 + 10 + 2}{4} \) = \( \frac{24}{4} \) = 6

The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).

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

5 + (4 + 4) ÷ 4 x 3 - 3²
P: 5 + (8) ÷ 4 x 3 - 3²
E: 5 + 8 ÷ 4 x 3 - 9
MD: 5 + \( \frac{8}{4} \) x 3 - 9
MD: 5 + \( \frac{24}{4} \) - 9
AS: \( \frac{20}{4} \) + \( \frac{24}{4} \) - 9
AS: \( \frac{44}{4} \) - 9
AS: \( \frac{44 - 36}{4} \)
\( \frac{8}{4} \)
2

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 4 workers at the company now and that's enough to staff 2 crews so there are \( \frac{4}{2} \) = 2 workers on a crew. 4 crews are needed for the busy season which, at 2 workers per crew, means that the roofing company will need 4 x 2 = 8 total workers to staff the crews during the busy season. The company already employs 4 workers so they need to add 8 - 4 = 4 new staff for the busy season.