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

3\( \sqrt{18} \) - 7\( \sqrt{2} \)
3\( \sqrt{9 \times 2} \) - 7\( \sqrt{2} \)
3\( \sqrt{3^2 \times 2} \) - 7\( \sqrt{2} \)
(3)(3)\( \sqrt{2} \) - 7\( \sqrt{2} \)
9\( \sqrt{2} \) - 7\( \sqrt{2} \)

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

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. 5 crews are needed for the busy season which, at 2 workers per crew, means that the roofing company will need 5 x 2 = 10 total workers to staff the crews during the busy season. The company already employs 4 workers so they need to add 10 - 4 = 6 new staff for the busy season.

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

5 + (2 + 4) ÷ 3 x 4 - 2²
P: 5 + (6) ÷ 3 x 4 - 2²
E: 5 + 6 ÷ 3 x 4 - 4
MD: 5 + \( \frac{6}{3} \) x 4 - 4
MD: 5 + \( \frac{24}{3} \) - 4
AS: \( \frac{15}{3} \) + \( \frac{24}{3} \) - 4
AS: \( \frac{39}{3} \) - 4
AS: \( \frac{39 - 12}{3} \)
\( \frac{27}{3} \)
9

The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).

The amount of flour you need is (3\(\frac{3}{8}\) - 1) cups. Rewrite the quantities so they share a common denominator and subtract:

(\( \frac{27}{8} \) - \( \frac{8}{8} \)) cups
\( \frac{19}{8} \) cups
2\(\frac{3}{8}\) cups