Which of the following interchanges in signs and numbers will make the given equation correct? `7 xx 9 + 5 = 68`
चिन्हों और संख्याओं में निम्न में से कौन-सा अंतविर्नियम दिए गए समीकरण को सही बना देगा?

Options

A. `+` and = 5 and 6 / `+` और = 5 और 6
B. `+ and =, 7 and 9` / + और = 7 और 9
C. x and + 5 and 7 / x और + 5 और 7
D. x and + and 9 / x और +7 और 9

Explanation

To solve the equation \( 7 \times 9 + 5 = 68 \) and determine which interchange of signs and numbers will make it correct, we will analyze each option provided.

### Step-by-Step Solution:

1. **Original Equation**:
The original equation is \( 7 \times 9 + 5 = 68 \).

2. **Evaluate the Original Equation**:
Let's calculate the left side of the equation:
\[ 7 \times 9 = 63 \]
Now add 5:
\[ 63 + 5 = 68 \]
So, the left side equals the right side, which means the original equation is already correct.

3. **Check Each Option**:
We will check the provided options one by one to see which one can also satisfy the equation.

**Option 1**: Replace the plus sign with an equal sign and replace 5 with 6.
- New equation: \( 7 \times 9 = 6 \)
- This is incorrect since \( 63 \neq 6 \).

**Option 2**: Interchange the plus sign and equal sign, and replace 7 and 9.
- New equation: \( 9 \times 7 + 5 = 68 \)
- This simplifies to \( 63 + 5 = 68 \), which is correct.

**Option 3**: Replace 5 with 7 and replace the multiplication sign with a plus sign.
- New equation: \( 7 + 9 \times 7 = 68 \)
- This simplifies to \( 7 + 63 = 70 \), which is incorrect.

**Option 4**: Replace multiplication with addition and replace 7 and 9.
- New equation: \( 9 + 7 \times 5 = 68 \)
- This simplifies to \( 9 + 35 = 44 \), which is incorrect.

4. **Conclusion**:
The only option that satisfies the equation is **Option 2**: Interchanging the plus sign and equal sign, and replacing 7 and 9.