The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] 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 [24, 48, 72, 96] making 24 the smallest multiple 6 and 8 have in common.

By buying two shirts, Bob will save $15 x \( \frac{40}{100} \) = \( \frac{$15 x 40}{100} \) = \( \frac{$600}{100} \) = $6.00 on the second shirt.

So, his total cost will be
$15.00 + ($15.00 - $6.00)
$15.00 + $9.00
$24.00

To add 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 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60]. The first few multiples they share are [6, 12, 18, 24, 30] making 6 the smallest multiple 2 and 6 share.

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

\( \frac{2 x 3}{2 x 3} \) + \( \frac{8 x 1}{6 x 1} \)

\( \frac{6}{6} \) + \( \frac{8}{6} \)

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

\( \frac{6 + 8}{6} \) = \( \frac{14}{6} \) = 2\(\frac{1}{3}\)

An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.

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

\( \frac{2}{8} \) x \( \frac{3}{7} \) = \( \frac{2 x 3}{8 x 7} \) = \( \frac{6}{56} \) = \(\frac{3}{28}\)