To solve for \( x \) in the equation \( \frac{3}{7} = \frac{x}{49} \), we can cross-multiply:
\[ 3 \cdot 49 = 7 \cdot x \]
This simplifies to:
\[ 147 = 7x \]
Next, divide both sides by 7 to isolate \( x \):
\[ x = \frac{147}{7} = 21 \]
Thus, the correct answer is:
21
1 answer