Answer:
x > 2, x < -8
Interval notation:
( -infinity, -8) U (2, infinity)
Explanation:
x(x+6) > 16
distribute x into x+6, multiply
x^2 + 6x > 16
bring 16 to left side, subtract
x^2 + 6x - 16 > 0
factors of -16 that add to +6 is -2 and +8
(x - 2)(x + 8) > 0
solve for x:
x < -8, x > 2
Interval notation:
( -infinity, -8) U (2, infinity)