4*(x - 1)*(7 - x) <= 9*x
(7 - x)*(4*(x - 1)) <= 9*x
(-oo, 7/4] U [4, oo)
x in Union(Interval(-oo, 7/4), Interval(4, oo))
Or(And(4 <= x, x < oo), And(x <= 7/4, -oo < x))
((4 <= x)∧(x < oo))∨((x <= 7/4)∧(-oo < x))