Answer: -8x² + 32x + 40
Step-by-step explanation:
I've included a picture in case you need clarification, feel free to write me a comment too.
y = -8 (x-5)(x+1)
Start by using the FOIL multiplication method on (x-5)(x+1)
1. x * x = x^2
2. x * 1 = x
3. -5 * x = -5x
4. -5 * 1 = -5
Combine all the terms to get: x² - 4x - 5
Now distribute the -8 we left out from earlier to each term (multiply -8):
-8 (x² - 4x - 5)
Your final answer should be:
-8x² + 32x + 40