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

A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.

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 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 4 and 8 share.

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

\( \frac{9 x 2}{4 x 2} \) - \( \frac{5 x 1}{8 x 1} \)

\( \frac{18}{8} \) - \( \frac{5}{8} \)

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

\( \frac{18 - 5}{8} \) = \( \frac{13}{8} \) = 1\(\frac{5}{8}\)

By buying two shirts, Charlie will save $44 x \( \frac{5}{100} \) = \( \frac{$44 x 5}{100} \) = \( \frac{$220}{100} \) = $2.20 on the second shirt.

The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.