To simplify the expression \( m^2 - 4 \cdot 2^4 \), we first evaluate \( 2^4 \):
\[ 2^4 = 16 \]
Now, substitute this value back into the expression:
\[ m^2 - 4 \cdot 16 \]
Next, calculate \( 4 \cdot 16 \):
\[ 4 \cdot 16 = 64 \]
Now, we can rewrite the expression:
\[ m^2 - 64 \]
Therefore, the expression \( m^2 - 4 \cdot 2^4 \) simplifies to:
\[ m^2 - 64 \]
This is the equivalent expression.