To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 5 are [5, 10, 15, 20, 25, 30, 35, 40, 45, 50] and the first few multiples of 7 are [7, 14, 21, 28, 35, 42, 49, 56, 63, 70]. The first few multiples they share are [35, 70] making 35 the smallest multiple 5 and 7 share.

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

\( \frac{3 x 7}{5 x 7} \) - \( \frac{6 x 5}{7 x 5} \)

\( \frac{21}{35} \) - \( \frac{30}{35} \)

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

\( \frac{21 - 30}{35} \) = \( \frac{-9}{35} \) = -\(\frac{9}{35}\)

By buying two shirts, Monty will save $38 x \( \frac{45}{100} \) = \( \frac{$38 x 45}{100} \) = \( \frac{$1710}{100} \) = $17.10 on the second shirt.

A number with an exponent (b^e) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b¹ = b) and a base with an exponent of 0 equals 1 ( (b⁰ = 1).

To divide terms with exponents, the base of both exponents must be the same. In this case they are so divide the coefficients and subtract the exponents:

\( \frac{2a^5}{8a^3} \)
\( \frac{2}{8} \) a^{(5 - 3)}
\(\frac{1}{4}\)a²

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

Solving for time:

time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{675mi}{75mph} \)
9 hours