Answer:
C
Step-by-step explanation:
x²-9x<-8
x²-9x+(-9/2)²<-8+(-9/2)²
(x-9/2)²<-8+81/4
(x-9/2)²<(-32+81)/4
(x-9/2)²<49/4
|x-9/2|<7/2
-7/2<x-9/2<7/2
add 9/2
9/2-7/2<x-9/2+9/2<7/2+9/2
2/2<x<16/2
1<x<8
