I can help you solve the math problems shown in your image. Let's go through them one by one:

1. $6 + (-4) =$

   • Adding a negative number is the same as subtraction:
     $6 - 4 = 2$

2. $(-1) + (-9) =$

   • Adding two negative numbers:
     $-1 + (-9) = -10$

3. $(-7) - (-8) =$

   • Subtracting a negative is the same as adding:
     $-7 + 8 = 1$

4. $\frac{-2}{3} - \frac{3}{4} =$

   • First, find a common denominator (12):
     $\frac{-2}{3} = \frac{-8}{12}, \quad \frac{3}{4} = \frac{9}{12}$
     Now subtract:
     $\frac{-8}{12} - \frac{9}{12} = \frac{-17}{12}$ So, $\frac{-2}{3} - \frac{3}{4} = \frac{-17}{12}$.

5. $6, 4, .1 (-6, 2) =$

   • The operation is unclear due to the formatting. Could you clarify what is meant here? It seems to be missing or miswritten.

6. $(-28) \div (-4) =$

   • Dividing two negative numbers gives a positive result:
     $-28 \div -4 = 7$

Would you like more details on any of these? Here are 5 related questions you could explore:

1. How do you add and subtract negative numbers?
2. What is the rule for dividing negative numbers?
3. How can you simplify fractions with different denominators?
4. Why does subtracting a negative become addition?
5. Can you further simplify improper fractions like $\frac{-17}{12}$?

Tip: When subtracting fractions, always find a common denominator first to make the operation easier!