To simplify the expression \( 7 - 4 \cdot 7 \sqrt{49} \), we first simplify \( \sqrt{49} \):
\[ \sqrt{49} = 7 \]
Now, substitute \( \sqrt{49} \) into the expression:
\[ 7 - 4 \cdot 7 \cdot 7 \]
Next, calculate \( 4 \cdot 7 \cdot 7 \):
\[ 4 \cdot 7 \cdot 7 = 4 \cdot 49 = 196 \]
Now substitute this back into the expression:
\[ 7 - 196 \]
This simplifies to:
\[ 7 - 196 = -189 \]
Since the problem requests a simplified fraction and represents negative exponents to be avoided, we can express \(-189\) as:
\[ -\frac{189}{1} \]
Thus, the simplified answer is:
\[ -\frac{189}{1} \]
If the requirement is only to express it as a positive fraction, note that we commonly represent negative values with a negative sign in front, and fractions do not typically represent negative values as the numerator, so the final answer remains:
\[ -189 \] or equivalently, as a fraction: \(-\frac{189}{1}\).