Jawabanmu

2014-08-22T05:21:58+07:00
=> 2x + y = 7
x=0 -> y=7 (0,7)
y=0 -> x=7/2 (7/2,0)
misal (0,0) = 2x0 + 0 ≥ 7 (Salah)

=> x+y = 5
x=0 -> y=5 (0,5)
y=0 -> x=5 (5,0)
misal (0,0) = 0 + 0 ≥ 5 (Salah)

Perpotongan garis :
7x + 7/2y = 49/2
5x+5y = 25
disederhanakan

14x + 7y = 49
  7x + 7y = 35
--------------------- -
7x = 14
x= 2

5x+5y = 25 => 5x2 +5y = 25
10+5y = 25
5y = 15
y=3

Titik perpotongan = (2,3)
nilai minimum f (2,3) = 4x + 5y = 4x2 + 5x3 = 8 + 15 = 23 (c)

7 3 7