To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [40, 80] making 40 the smallest multiple 8 and 10 share.

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

\( \frac{5 x 5}{8 x 5} \) - \( \frac{2 x 4}{10 x 4} \)

\( \frac{25}{40} \) - \( \frac{8}{40} \)

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

\( \frac{25 - 8}{40} \) = \( \frac{17}{40} \) = \(\frac{17}{40}\)

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{15 + 13 + 18 + 10}{4} \) = \( \frac{56}{4} \) = 14

A prime number is an integer greater than 1 that has no factors other than 1 and itself. Examples of prime numbers include 2, 3, 5, 7, and 11.

To divide terms with radicals, divide the coefficients and radicands separately:

\( \frac{8\sqrt{9}}{4\sqrt{3}} \)
\( \frac{8}{4} \) \( \sqrt{\frac{9}{3}} \)
2 \( \sqrt{3} \)

To raise a term with an exponent to another exponent, retain the base and multiply the exponents: