If "`div`" denotes "multiplication", "-" denotes "addition", "+" denotes "division" and "`xx`" denites "subtraction", then which of the following is the value of the expression
`19 div 9 xx 51 - 171 + 19`
A. 143
B. 129
C. 179
D. 151

Options

A. B
B. C
C. A
D. D

Answer

To solve the expression `19 div 9 xx 51 - 171 + 19` with the given operations, we first need to replace the symbols according to the definitions provided:

- `div` denotes multiplication (×)
- `-` denotes addition (+)
- `+` denotes division (÷)
- `xx` denotes subtraction (−)

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

1. Replace `div` with `×`:
- `19 div 9` becomes `19 × 9`

2. Replace `xx` with `−`:
- `9 xx 51` becomes `9 − 51`

3. Replace `-` with `+`:
- `- 171` becomes `+ 171`

4. Replace `+` with `÷`:
- `+ 19` becomes `÷ 19`

So, the expression now looks like this:
\[ 19 × 9 − 51 + 171 ÷ 19 \]

Next, we will evaluate the expression step by step, following the order of operations (BODMAS/BIDMAS rules):

1. **Calculate the multiplication and division first:**
- \( 19 × 9 = 171 \)
- \( 171 ÷ 19 = 9 \)

2. **Now substitute these values back into the expression:**
- The expression now becomes:
\[ 171 − 51 + 9 \]

3. **Perform the subtraction and addition from left to right:**
- First, calculate \( 171 − 51 = 120 \)
- Then, add \( 120 + 9 = 129 \)

Thus, the final value of the expression is **129**.

### Final Answer:
**B. 129**