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

Solving for distance:

distance = \( \text{speed} \times \text{time} \)
distance = \( 20mph \times 2h \)
40 miles

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

To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 2 are [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] and the first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80]. The first few multiples they share are [8, 16, 24, 32, 40] making 8 the smallest multiple 2 and 8 share.

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

\( \frac{9 x 4}{2 x 4} \) - \( \frac{9 x 1}{8 x 1} \)

\( \frac{36}{8} \) - \( \frac{9}{8} \)

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

\( \frac{36 - 9}{8} \) = \( \frac{27}{8} \) = 3\(\frac{3}{8}\)

1

A ratio of 4:1 means that there are 4 home fans for every one visiting fan. So, of every 5 fans, 4 are home fans and \( \frac{4}{5} \) of every fan in the stadium is a home fan:

39,000 fans x \( \frac{4}{5} \) = \( \frac{156000}{5} \) = 31,200 fans.