To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 14 are [14, 28, 42, 56, 70, 84, 98]. The first few multiples they share are [42, 84] making 42 the smallest multiple 6 and 14 share.

Next, convert the fractions so each denominator equals the lowest common multiple:

\( \frac{2 x 7}{6 x 7} \) - \( \frac{4 x 3}{14 x 3} \)

\( \frac{14}{42} \) - \( \frac{12}{42} \)

Now, because the fractions share a common denominator, you can subtract them:

\( \frac{14 - 12}{42} \) = \( \frac{2}{42} \) = \(\frac{1}{21}\)

Average speed in miles per hour is the number of miles traveled divided by the number of hours:

The number of students taking German or Spanish is 5 + 9 = 14. Of that group of 14, 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 14 - 2 = 12 who are taking at least one language. 21 - 12 = 9 students who are not taking either language.

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:

8z² + 1z²
(8 + 1)z²
9z²

The greatest common factor (GCF) is the greatest factor that divides two integers.