Question

Tentukan nilai minimum f(x,y) = 3x + 2y !!!

Answer 1

Titik potong
15x+18y = 270 |×4
20x+12y = 240 |×3

60x + 72y = 1080
60x + 36y = 720
_____________-
36y = 360
y = 360/36
y = 10

y disubstitusikan
20x + 12.10 = 240
20x + 120 = 240
20x = 240-120
20x = 120
x = 120/20
x = 6

titik potong = (6,10)

f(x, y) = 3x + 2y
f(0,0) = 3.0 + 2.0 = 0
f(12,0) = 3.12 + 2.0 = 36
f(6,10) = 3.6 + 2.10 = 38
f(0,15) = 3.0 + 2.15 = 30

jadi, nilai minimumnya adalah 0