To add these distances, they must share the same unit so first you need to first convert the swim distance from meters (m) to kilometers (km) before adding it to the bike and run distances which are already in km. To convert 400 meters to kilometers, divide the distance by 1000 to get 0.4km then add the remaining distances:

total distance = swim + bike + run
total distance = 0.4km + 30.9km + 12.6km
total distance = 43.9km

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

2 + (2 + 5) ÷ 3 x 5 - 2²
P: 2 + (7) ÷ 3 x 5 - 2²
E: 2 + 7 ÷ 3 x 5 - 4
MD: 2 + \( \frac{7}{3} \) x 5 - 4
MD: 2 + \( \frac{35}{3} \) - 4
AS: \( \frac{6}{3} \) + \( \frac{35}{3} \) - 4
AS: \( \frac{41}{3} \) - 4
AS: \( \frac{41 - 12}{3} \)
\( \frac{29}{3} \)
9\(\frac{2}{3}\)

The number of students taking German or Spanish is 7 + 5 = 12. Of that group of 12, 3 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 12 - 3 = 9 who are taking at least one language. 21 - 9 = 12 students who are not taking either language.

70% of the water consumption is industrial use and 35% is personal use so (70% - 35%) = 35% more water is used for industrial purposes. 10,000 gallons are consumed daily so industry consumes \( \frac{35}{100} \) x 10,000 gallons = 3,500 gallons.

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).