For a quadratic equation \( ax^2 + bx + c = 0 \):
- Product of roots: \( \alpha \beta = \frac{c}{a} \).
Given:
\[
\alpha \beta = -4, \quad a = 1, \quad c = p.
\]
\[
\frac{p}{1} = -4 \Rightarrow p = -4.
\]
Since the equation is given as \( x^2 - 5x + p = 10 \), we solve for \( p \):
\[
p = -4 + 10 = 6.
\]