18/[(4-7)+5]

-4*5-8/2

To solve these arithmetic expressions, we need to follow the order of operations, also known as PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction).

Let's solve them step by step:

Expression: 18/[(4-7)+5]

Step 1: Simplify the expression within the parentheses.
Inside the parentheses, we have (4-7) which equals -3. Therefore, the expression simplifies to 18/[(-3) + 5].

Step 2: Perform the addition inside the brackets.
(-3) + 5 = 2.
So, the expression becomes 18/2.

Step 3: Perform the division.
18 divided by 2 equals 9.
Therefore, the final answer is 9.

Expression: -4*5-8/2

Step 1: Perform the multiplication.
-4 multiplied by 5 equals -20.
So, the expression becomes -20 - 8/2.

Step 2: Perform the division.
8 divided by 2 equals 4.
So, the expression becomes -20 - 4.

Step 3: Perform the subtraction.
-20 - 4 equals -24.
Therefore, the final answer is -24.