By buying two shirts, Damon will save $35 x \( \frac{15}{100} \) = \( \frac{$35 x 15}{100} \) = \( \frac{$525}{100} \) = $5.25 on the second shirt.

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

To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [20, 40, 60, 80] making 20 the smallest multiple 4 and 10 share.

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

\( \frac{8 x 5}{4 x 5} \) - \( \frac{9 x 2}{10 x 2} \)

\( \frac{40}{20} \) - \( \frac{18}{20} \)

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

\( \frac{40 - 18}{20} \) = \( \frac{22}{20} \) = 1\(\frac{1}{10}\)

To divide fractions, invert the second fraction and then multiply:

\( \frac{3}{5} \) ÷ \( \frac{4}{5} \) = \( \frac{3}{5} \) x \( \frac{5}{4} \)

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{3}{5} \) x \( \frac{5}{4} \) = \( \frac{3 x 5}{5 x 4} \) = \( \frac{15}{20} \) = \(\frac{3}{4}\)

To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:

\( \sqrt{\frac{36}{16}} \)
\( \frac{\sqrt{36}}{\sqrt{16}} \)
\( \frac{\sqrt{6^2}}{\sqrt{4^2}} \)
\( \frac{6}{4} \)
1\(\frac{1}{2}\)