Let's solve each expression step by step:

1. $1 + 4 = 5$

2. $9 - 2 \times 3 = 9 - 6 = 3$
   (Remember, multiplication is done before subtraction due to the order of operations, also known as PEMDAS/BODMAS rules.)

3. $(7 - 5) \times (3 + 1) = 2 \times 4 = 8$
   (First, evaluate inside the parentheses, then multiply the results.)

Final answers:

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

Would you like any details or further explanations?

Here are some related questions for practice:

1. $8 + 6 \times 2 - 3 =$
2. $(10 - 3) \times (5 + 2) =$
3. $15 - 4 \times 2 + 6 =$
4. $(6 + 2) \div 2 \times 3 =$
5. $(12 - 4) \times (2 + 3) =$

Tip: Always perform multiplication and division before addition and subtraction when solving expressions without parentheses!