To evaluate the expression $-\frac{1}{4} - \frac{3}{5}$, we need to follow these steps:

1. Find a common denominator.
2. Rewrite each fraction with the common denominator.
3. Subtract the fractions.

Step 1: Find a Common Denominator

The denominators are 4 and 5. The least common multiple (LCM) of 4 and 5 is 20. So, the common denominator is 20.

Step 2: Rewrite Each Fraction with the Common Denominator

We need to convert $-\frac{1}{4}$ and $-\frac{3}{5}$ to fractions with the denominator of 20.

• For $-\frac{1}{4}$: $-\frac{1}{4} = -\frac{1 \times 5}{4 \times 5} = -\frac{5}{20}$

• For $-\frac{3}{5}$: $-\frac{3}{5} = -\frac{3 \times 4}{5 \times 4} = -\frac{12}{20}$

Step 3: Subtract the Fractions

Now we can subtract the fractions: $-\frac{5}{20} - \frac{12}{20} = -\frac{5 + 12}{20} = -\frac{17}{20}$

So, the evaluated expression is: $-\frac{17}{20}$

Would you like more details or have any questions about this calculation?

Here are 8 related questions you might find useful:

1. How do you find the least common multiple of two numbers?
2. Can you explain how to convert a fraction to an equivalent fraction with a different denominator?
3. What is the process for adding or subtracting fractions with different denominators?
4. How do you simplify a fraction after performing an arithmetic operation?
5. What are some common mistakes to avoid when working with fractions?
6. Can you show a detailed example of adding two fractions with different denominators?
7. How do you handle mixed numbers in fraction addition or subtraction?
8. What is the importance of the order of operations in arithmetic calculations involving fractions?

Tip: When working with fractions, always ensure that you find the correct common denominator to simplify addition and subtraction processes.