Which best describes the nature of photosynthesis?

Notes before we start solving:
+ve number * +ve number = +ve number
-ve number * -ve number = +ve number
+ve number * -ve number = -ve number

Now, the expression we have is:
(3x – 5)(–x + 4)
The distributive property gives us:
(3x)(–x) + (3x)(4) + (–5)(–x) + (–5)(4)

Now, to simplify this expression, we will multiply the terms as follows:
-3x^2 + 12x + 5x - 20
This will give us a final result:
-3x^2 + 17x - 20