9514 1404 393
Answer:
x ∈ (-∞, 9) U (-1, ∞)
Step-by-step explanation:
Get the absolute value by itself. Do that by multiplying by 4.
|3x +15| > 12
This resolves to two cases:
3x +15 > 12
x +5 > 4 . . . . divide by 3
x > -1 . . . . . . .subtract 5
-(3x +15) > 12
x +5 < -4 . . . . divide by -3
x < -9 . . . . . . . subtract 5
Then the solution in interval notation is ...
x ∈ (-∞, 9) U (-1, ∞)
