To expand and simplify $(m + 5)(m - 8)$, we use the distributive property (also known as the FOIL method for binomials):

Steps:

1. Multiply the first terms:
   $m \cdot m = m^2$

2. Multiply the outer terms:
   $m \cdot -8 = -8m$

3. Multiply the inner terms:
   $5 \cdot m = 5m$

4. Multiply the last terms:
   $5 \cdot -8 = -40$

Combine all terms:

$m^2 - 8m + 5m - 40$

Simplify like terms:

$m^2 - 3m - 40$

Final Answer:

$m^2 - 3m - 40$

Would you like a breakdown of a similar example or have any further questions?

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Here are 5 related questions to expand your understanding:

1. How do you apply the distributive property to expressions with more than two terms?
2. What happens when both terms in the binomial are negative?
3. Can you explain how the FOIL method works in detail?
4. How do you factorize the expression $m^2 - 3m - 40$?
5. How would this change if the binomial was cubed instead of squared?

Tip: When simplifying expressions, always combine like terms carefully to avoid errors.