If ` xx `means `-:` , - means ` xx , -:` means + and + means -, then `(3 - 15 -: 19) xx 8 + 6 = ?`

Options

A. 8
B. 4
C. 2
D. `-1`

Explanation

To solve the expression `(3 - 15 -: 19) xx 8 + 6`, we first need to interpret the symbols according to the definitions provided:

- `xx` means `-:`
- `-` means `xx`
- `-:` means `+`
- `+` means `-`

Now, let's rewrite the expression using these definitions:

1. Replace `-` with `xx`:
- `(3 xx 15 -: 19) xx 8 + 6`

2. Replace `-:` with `+`:
- `(3 xx 15 + 19) xx 8 + 6`

3. Replace `xx` with `-:`:
- `(3 -: 15 + 19) -: 8 + 6`

4. Replace `+` with `-`:
- `(3 -: 15 - 19) -: 8 - 6`

Now we need to evaluate the expression step by step:

### Step 1: Evaluate the expression inside the brackets
We have `3 -: 15 - 19`. According to the definitions:
- `-:` means `+`, so we can rewrite it as:
- `3 + 15 - 19`

Now calculate:
- `3 + 15 = 18`
- `18 - 19 = -1`

### Step 2: Substitute back into the expression
Now we substitute `-1` back into the expression:
- `(-1) -: 8 - 6`

### Step 3: Evaluate `-1 -: 8`
Using the definition:
- `-:` means `+`, so:
- `-1 + 8 = 7`

### Step 4: Substitute back into the expression
Now we have:
- `7 - 6`

### Step 5: Evaluate `7 - 6`
Using the definition:
- `-` means `xx`, so:
- `7 xx 6` which means `7 - 6 = 1`

Thus, the final answer is:
- **1**