12
------------ <= 0
2
4 + 3*x - x
12/(-x^2 + 3*x + 4) <= 0
x0 = 0
3 <= 0
3 >= 0
Or(And(4 < x, x < oo), x < -1)
(x < -1)∨((4 < x)∧(x < oo))
(-oo, -1) U (4, oo)
x in Union(Interval.open(-oo, -1), Interval.open(4, oo))