Answer:
Step-by-step explanation:
Take out a common factor of 2
2(r^2 - 2r - 8) Now factor.
2(r - 4)(r + 2)
Answer: r=4,-2
2r^2-4r-16=0
2(r^2-2r-8)=0
2(r-4)(r+2)=0
r=4,-2