By buying two shirts, Charlie will save $17 x \( \frac{50}{100} \) = \( \frac{$17 x 50}{100} \) = \( \frac{$850}{100} \) = $8.50 on the second shirt.

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

The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).

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

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

\( \frac{3}{7} \) ÷ \( \frac{2}{6} \) = \( \frac{3}{7} \) x \( \frac{6}{2} \)

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

\( \frac{3}{7} \) x \( \frac{6}{2} \) = \( \frac{3 x 6}{7 x 2} \) = \( \frac{18}{14} \) = 1\(\frac{2}{7}\)