No. 20 mohon dijawab disertai penjelasannya. Kalau bisa sama no.19 hehe. Terimakasih.

20) Garis m melalui titik (2, 1) dan (5, -1)
Persamaan garis m
(y2 - y1)/(x2 - x1) = (y - y1)/(x - x1)
(-1 - 1)/(5 - 2) = (y - 1)/(x - 2)
-2/3 = (y - 1)/(x - 2)
3(y - 1) = -2(x - 2)
3y - 3 = -2x + 4
3y = -2x + 7
y = -2/3 x + 7/3

19) (2 - 3x)/(3 - x) ≥ 4
(2 - 3x)/(3 - x) - 4 ≥ 0
(2 - 3x - 4(3 - x))/(3 - x) ≥ 0
(2 - 3x - 12 + 4x) / (3 - x) ≥ 0
(x - 10)/(3 - x) ≥ 0
x = 10 atau x = 3
garis bilangan
--- (3) +++ (10) ----
3 < x ≤ 10