To divide fractions, you can multiply by the reciprocal of the second fraction. So for the expression \( \frac{4}{5} \div \frac{6}{7} \), you can rewrite it as:
\[ \frac{4}{5} \times \frac{7}{6} \]
Next, multiply the numerators and the denominators:
\[ \frac{4 \times 7}{5 \times 6} = \frac{28}{30} \]
Now, simplify \( \frac{28}{30} \) by finding the greatest common divisor (GCD) of 28 and 30, which is 2:
\[ \frac{28 \div 2}{30 \div 2} = \frac{14}{15} \]
Thus, the answer in simplest form is:
\[ \frac{14}{15} \]