I see the image contains several mathematical expressions. Let me solve each one for you:

1. 5.3 + 5.7
   $5.3 + 5.7 = 11$

2. 143 - 6
   $143 - 6 = 137$

3. 7 ÷ 100
   $7 \div 100 = 0.07$

4. 4 + 3c
   This is an algebraic expression. Without knowing the value of $c$, it simplifies to $4 + 3c$.

Let me know if you need further explanation or additional details.

Here are five related questions:

1. What is the result of $7.8 + 3.2$?
2. Solve $200 - 50$.
3. What is $9 ÷ 0.5$?
4. Simplify $5 + 4x$ when $x = 2$.
5. What is the decimal form of $\frac{3}{25}$?

Tip: Always check your answers for small addition or subtraction mistakes to ensure accuracy!