It seems like you provided two numbers, $-\frac{4}{5}$ and $28$. Could you please clarify what you would like to do with these numbers? For example:

1. Do you want to add, subtract, multiply, or divide these numbers?
2. Are these coordinates of a point or related to another mathematical concept?
3. Do you need to solve an equation involving these numbers?

Please specify the problem, and I'll be happy to help!

Would you like more details or have any questions? Here are 5 possible directions:

1. How to multiply a fraction by a whole number.
2. Operations involving fractions and whole numbers.
3. Converting between fractions and decimals.
4. Simplifying fractions.
5. Solving basic algebraic equations with fractions.

Tip: When dealing with fractions, remember that multiplying or dividing is usually simpler than adding or subtracting, as it doesn't require a common denominator.