Respuesta :

A and D are the solutions that make the inequality true.
6^2= 36
9^2= 81
10^2= 100
-4^2= 16
-9^2+ 81
-12^2= 144
x^2 < 81
x< -9 and x > 9 
means
-9 < x < 9

A. -9 < 6  < 9 True
B. -9 < 9  < 9 False ( 9 = 9)
C. -9 < 10 < 9 False ( 10>9)
D. -9 < -4 < 9 True
E. -9 < -9 < 9 False ( -9 = -9)
F. -9 < -12 < 9 False ( -12 < -9)

so answer 
A. 6
D. -4