Answer:
-3 and -5
Step-by-step explanation:
Why it is, is you are putting your equation into two separate parts.
(r-__)(r-__). That will give you the r^2.
You then have to think of the -8 and the 15. When you times -3 and -5 together you get 15, and if you add it together you get -8.
So it will be (r-3)(r-5).
How this is, is you will do FOIL.
F=FRONT. You do the r's to get r^2.
O=OUTER. You add the r and the -5 (which are the outer) to get -5.
I=INNER. You add the other r and the -3 (which are the inner) to get -3.
L=LAST. You times the -3 and the -5 (which are last) to get 15.
You then put it together to get r^2-8r+15=0.
So your answers are -3 and -5.
