The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:

interest = annual interest rate x loan amount

i = (\( \frac{6}{100} \)) x $1,400
i = 0.08 x $1,400
i = $112

To subtract these radicals together their radicands must be the same:

3\( \sqrt{63} \) - 7\( \sqrt{7} \)
3\( \sqrt{9 \times 7} \) - 7\( \sqrt{7} \)
3\( \sqrt{3^2 \times 7} \) - 7\( \sqrt{7} \)
(3)(3)\( \sqrt{7} \) - 7\( \sqrt{7} \)
9\( \sqrt{7} \) - 7\( \sqrt{7} \)

Now that the radicands are identical, you can subtract them:

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

\( \frac{1}{5} \) ÷ \( \frac{3}{6} \) = \( \frac{1}{5} \) x \( \frac{6}{3} \)

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

\( \frac{1}{5} \) x \( \frac{6}{3} \) = \( \frac{1 x 6}{5 x 3} \) = \( \frac{6}{15} \) = \(\frac{2}{5}\)

To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 14 are [14, 28, 42, 56, 70, 84, 98]. The first few multiples they share are [42, 84] making 42 the smallest multiple 6 and 14 share.

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

\( \frac{8 x 7}{6 x 7} \) - \( \frac{7 x 3}{14 x 3} \)

\( \frac{56}{42} \) - \( \frac{21}{42} \)

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

\( \frac{56 - 21}{42} \) = \( \frac{35}{42} \) = \(\frac{5}{6}\)

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

\( \frac{9 + 3 + 8 + 4}{4} \) = \( \frac{24}{4} \) = 6