If $4-3x$ ≥ 19, then the real values of $x$ are described by:

$4-3x$ ≥ 19 gives $-3x$ ≥ 15. Dividing by the negative number −3 reverses the inequality sign, so $x$ ≤ −5. (At $x=-6$: 4 + 18 = 22 ≥ 19 is true; at $x=0$: 4 ≥ 19 is false.)