To find the value of \( M - N \), we first need to determine the expressions for \( M \) and \( N \).
Given: \[ M = 5x^2 + 7x - 4 \] \[ N = 4x - 4x + 5 \]
Next, we simplify \( N \): \[ N = 4x - 4x + 5 = 0 + 5 = 5 \]
Now we can find \( M - N \): \[ M - N = (5x^2 + 7x - 4) - 5 \]
Simplifying this expression: \[ M - N = 5x^2 + 7x - 4 - 5 \] \[ M - N = 5x^2 + 7x - 9 \]
Therefore, the value of \( M - N \) is: \[ \boxed{5x^2 + 7x - 9} \]