tolong dijawab yang jenius mtk plis. besok dikumpulin

3) 2x^2 - 13x - 7 = 0
(2x + 1)(x - 7) = 0
x = -1/2 atau x = 7
x2 > x1 maka
x2 = 7 dan x1 = -1/2
2.x1 + 3.x2 = 2(-1/2) + 3(7) = -1 + 21 = 20

4) x^2 + 4x - 5 ≤ 0
(x + 5)(x - 1) ≤ 0
x = -5 atau x = 1
Garis bilangan
+++ (-5) --- (1) +++
-5 ≤ x ≤ 1