To find the product of (x - 5) and (x - 4), we can begin by simplifying with the distributive property:
(x - 5)(x - 4) = x(x - 4) - 5(x - 4)
Now we distribute accordingly:
x(x - 4) = x^2 - 4x
-5(x - 4) = -5x + 20
Next, we combine the simplified terms:
x^2 - 4x - 5x + 20
Lastly, we combine like terms:
x^2 - 9x + 20
Hence, (x - 5)(x - 4) = x^2 - 9x + 20.