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

To simplify a radical, factor out the perfect squares:

\( \sqrt{80} \)
\( \sqrt{16 \times 5} \)
\( \sqrt{4^2 \times 5} \)
4\( \sqrt{5} \)

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

5 + (5 + 5) ÷ 5 x 3 - 4²
P: 5 + (10) ÷ 5 x 3 - 4²
E: 5 + 10 ÷ 5 x 3 - 16
MD: 5 + \( \frac{10}{5} \) x 3 - 16
MD: 5 + \( \frac{30}{5} \) - 16
AS: \( \frac{25}{5} \) + \( \frac{30}{5} \) - 16
AS: \( \frac{55}{5} \) - 16
AS: \( \frac{55 - 80}{5} \)
\( \frac{-25}{5} \)
-5

The number of students taking German or Spanish is 11 + 8 = 19. Of that group of 19, 2 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 19 - 2 = 17 who are taking at least one language. 29 - 17 = 12 students who are not taking either language.

The amount of flour you need is (3\(\frac{1}{8}\) - \(\frac{1}{4}\)) cups. Rewrite the quantities so they share a common denominator and subtract:

(\( \frac{25}{8} \) - \( \frac{2}{8} \)) cups
\( \frac{23}{8} \) cups
2\(\frac{7}{8}\) cups