The problem consists of two parts: (7) Calculate $8/3 \div 4/5$. (9) Calculate $12 \div 8/11$.

1. Problem Description

The problem consists of two parts:

(7) Calculate $8/3 \div 4/5$.

(9) Calculate $12 \div 8/11$.

2. Solution Steps

(7) To divide by a fraction, we multiply by its reciprocal.

$a/b \div c/d = a/b \times d/c$

So, $8/3 \div 4/5 = 8/3 \times 5/4$.

$8/3 \times 5/4 = (8 \times 5) / (3 \times 4) = 40/12$.

We can simplify $40/12$ by dividing both numerator and denominator by their greatest common divisor, which is

4. $40/12 = (40 \div 4) / (12 \div 4) = 10/3$.

(9) Similarly, to divide by a fraction, we multiply by its reciprocal.

$a \div c/d = a \times d/c$

So, $12 \div 8/11 = 12 \times 11/8$.

$12 \times 11/8 = (12 \times 11) / 8 = 132/8$.

We can simplify $132/8$ by dividing both numerator and denominator by their greatest common divisor, which is

4. $132/8 = (132 \div 4) / (8 \div 4) = 33/2$.

3. Final Answer

(7) $10/3$

(9) $33/2$