(-7+p)(8+p)

To simplify the expression (-7+p)(8+p), you can use the distributive property of multiplication over addition.

Start by distributing the first term, -7, to both terms inside the parentheses:
(-7)(8) + (-7)(p)

This simplifies to:
-56 - 7p

Next, distribute the second term, p, to both terms inside the parentheses:
8p + p^2

Now, we have the simplified expression:
-56 - 7p + 8p + p^2

Combine like terms:
p^2 + p - 7p - 56

Finally, simplify further by combining like terms:
p^2 - 6p - 56

Thus, the simplified expression of (-7+p)(8+p) is p^2 - 6p - 56.