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

\( \frac{3}{7} \) x \( \frac{2}{9} \) = \( \frac{3 x 2}{7 x 9} \) = \( \frac{6}{63} \) = \(\frac{2}{21}\)

A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:

5a⁶ + 2a⁶
(5 + 2)a⁶
7a⁶

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

\( \frac{2}{8} \) ÷ \( \frac{4}{5} \) = \( \frac{2}{8} \) x \( \frac{5}{4} \)

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

\( \frac{2}{8} \) x \( \frac{5}{4} \) = \( \frac{2 x 5}{8 x 4} \) = \( \frac{10}{32} \) = \(\frac{5}{16}\)

By buying two shirts, Alex will save $32 x \( \frac{40}{100} \) = \( \frac{$32 x 40}{100} \) = \( \frac{$1280}{100} \) = $12.80 on the second shirt.

So, his total cost will be
$32.00 + ($32.00 - $12.80)
$32.00 + $19.20
$51.20