If `x/21=7/3` then x = ?

Answer

To solve the equation \( \frac{x}{21} = \frac{7}{3} \), we can follow these steps:

### Step-by-Step Solution:

1. **Start with the given equation**:
\[ \frac{x}{21} = \frac{7}{3} \]

2. **Cross-multiply**:
To eliminate the fractions, we can cross-multiply:
\[ x \cdot 3 = 7 \cdot 21 \]

3. **Calculate the right side**:
Now, calculate \( 7 \cdot 21 \):
\[ 7 \cdot 21 = 147 \]
So the equation now looks like:
\[ 3x = 147 \]

4. **Solve for \( x \)**:
To find \( x \), divide both sides by 3:
\[ x = \frac{147}{3} \]

5. **Calculate the division**:
Now perform the division:
\[ x = 49 \]

### Final Answer:
Thus, the value of \( x \) is:
\[ \boxed{49} \]