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Kelas 11 Matematika
Bab Program Linear

40x + 20y <= 20 . 40
2x + y <= 40

30x + 40y <= 30 . 40
3x + 4y <= 120

2x + y = 40
y = -2x + 40

3x + 4y = 120
3x + 4 (-2x + 40) = 120
3x - 8x + 160 = 120
-5x = 120 - 160
x = -40/-5
x = 8

y = -2x + 40
y = -2 . 8 + 40
y = -16 + 40
y = 24

(8, 24)
(20, 0)
(0, 30)

f(x, y) = 3x + 2y

f(8, 24)
= 3 . 8 + 2 . 24
= 24 + 48
= 72

f(20, 0)
= 3 . 20 + 0
= 60

f(0, 30)
= 0 + 2 . 30
= 60

Nilai maksimum = 72

✩✩ D ✩✩