ANSWER
[tex] \frac{a + 3}{8} [/tex]
EXPLANATION
We want to simplify
[tex] \frac{a + 3}{a} \div \frac{8}{a} [/tex]
We multiply the first fraction by the reciprocal of the second fraction to obtain,
[tex] \frac{a + 3}{a} \times \frac{a}{8} [/tex]
We cancel the common factors to get,
[tex] \frac{a + 3}{1} \times \frac{1}{8} [/tex]
This gives us,
[tex] \frac{a + 3}{8} [/tex]