Powers and Roots: Using powers

$6\sqrt{4}:6\sqrt{4}=$

$4$

$\frac{21:\sqrt{49}+2}{8-(2+2\times3)}=$

In the numerator we solve the square root exercise:

$\sqrt{49}=7$

In the denominator we solve the exercise within parentheses:

$(2+2\times3)=$

$2+6=8$

The exercise we now have is:

$\frac{21:7+2}{8-8}=$

We solve the exercise in the numerator of fractions from left to right:

$21:7=3$

$3+2=5$

We obtain the exercise:

$\frac{5}{8-8}=\frac{5}{0}$

Since it is impossible for the denominator of the fraction to be 0, it is impossible to solve the exercise.

Cannot be solved

What is the result of the following power?

$(\frac{2}{3})^3$

$\frac{8}{27}$