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

3\( \sqrt{27} \) - 7\( \sqrt{3} \)
3\( \sqrt{9 \times 3} \) - 7\( \sqrt{3} \)
3\( \sqrt{3^2 \times 3} \) - 7\( \sqrt{3} \)
(3)(3)\( \sqrt{3} \) - 7\( \sqrt{3} \)
9\( \sqrt{3} \) - 7\( \sqrt{3} \)

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

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.

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

A factorial is the product of an integer and all the positive integers below it. To solve a fraction featuring factorials, expand the factorials and cancel out like numbers:

\( \frac{4!}{2!} \)
\( \frac{4 \times 3 \times 2 \times 1}{2 \times 1} \)
\( \frac{4 \times 3}{1} \)
\( 4 \times 3 \)
12

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

7z⁶ x 5z⁵
(7 x 5)z^{(6 + 5)}
35z¹¹