The given expression is:

$n = \frac{2}{7 \times 6} + \frac{81}{2} - \frac{2}{3 \times 4}$

To solve this, follow these steps:

1. Evaluate the denominators in the fractions:

   • $7 \times 6 = 42$
   • $3 \times 4 = 12$

2. Substitute the evaluated denominators back into the expression:

$n = \frac{2}{42} + \frac{81}{2} - \frac{2}{12}$

3. Simplify the fractions:
   • $\frac{2}{42} = \frac{1}{21}$
   • $\frac{2}{12} = \frac{1}{6}$

Now the expression becomes:

$n = \frac{1}{21} + \frac{81}{2} - \frac{1}{6}$

4. Find a common denominator to combine all the fractions. The least common denominator (LCD) of 21, 2, and 6 is 42.

   • Convert $\frac{1}{21}$ to $\frac{2}{42}$
   • Convert $\frac{81}{2}$ to $\frac{1701}{42}$
   • Convert $\frac{1}{6}$ to $\frac{7}{42}$

Now the expression becomes:

$n = \frac{2}{42} + \frac{1701}{42} - \frac{7}{42}$

5. Combine the fractions:

$n = \frac{2 + 1701 - 7}{42} = \frac{1696}{42}$

6. Simplify $\frac{1696}{42}$:

$n = \frac{848}{21} \approx 40.38$

Thus, the value of $n \approx 40.38$.

Would you like more details or have any questions?

Here are 5 related questions:

1. What is the least common denominator (LCD) of 12 and 18?
2. How do you simplify the expression $\frac{12}{36} + \frac{5}{6}$?
3. What is the value of $n$ in the equation $n = \frac{3}{4} + \frac{5}{8} - \frac{2}{3}$?
4. How can you add and subtract mixed fractions, such as $2 \frac{1}{3} + 4 \frac{2}{5} - 3 \frac{1}{2}$?
5. How would you calculate the value of $n$ in the expression $n = 5.7 + \frac{2}{3} - \frac{1}{4}$?

Tip: When adding or subtracting fractions, always find the least common denominator to simplify calculations.