To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 3 are [3, 6, 9, 12, 15, 18, 21, 24, 27, 30] and the first few multiples of 11 are [11, 22, 33, 44, 55, 66, 77, 88, 99]. The first few multiples they share are [33, 66, 99] making 33 the smallest multiple 3 and 11 share.

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

\( \frac{2 x 11}{3 x 11} \) - \( \frac{7 x 3}{11 x 3} \)

\( \frac{22}{33} \) - \( \frac{21}{33} \)

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

\( \frac{22 - 21}{33} \) = \( \frac{1}{33} \) = \(\frac{1}{33}\)

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

-1c⁷ - 7c⁷
(-1 - 7)c⁷
-8c⁷

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

A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.

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

\( \frac{11 + 3 + 11 + 3}{4} \) = \( \frac{28}{4} \) = 7