1) 3 single roots at x=2, 4, and -1
2) positive
3) 3rd degree
The answer would be 21 I believe
9 (a - b) + 5 (2a - 2b)
mutiply the first bracket by 9
(9)(a)= 9a
(9)(-b)= -9b
mutiply the second bracket by 5
(5)(2a)=10a
(5)(-2b)= -10b
9a-9b+10a-10b
9a+10a-9b-10b ( combine like terms<em>)</em>
Answer : C. 19a - 19b
I think that the answer would be 9/80, I used a calculator and double checked, so I think that it is correct.
Good Luck, Hope I helped:)