Let's solve these step by step:

1. $1 + 4 = 5$
2. $9 - 2 \times 3 = 9 - 6 = 3$ (Remember, multiplication comes before subtraction according to the order of operations.)
3. $(7 - 5) \times (3 + 1) = 2 \times 4 = 8$

So the solutions are:

1. $1 + 4 = 5$
2. $9 - 2 \times 3 = 3$
3. $(7 - 5) \times (3 + 1) = 8$

Would you like more details or have any questions?

Here are some related questions to explore:

1. What is the order of operations and why is it important?
2. How do parentheses affect the order of operations?
3. How would the result change if parentheses were placed differently in the second expression?
4. Can you create more expressions using a combination of operations like addition, subtraction, and multiplication?
5. What is the difference between using parentheses and without them in an expression?

Tip: Always remember the order of operations by using PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction).