tolong dibantu yahh secepatnya

garis 1
3x + 6y = 3×6
3x + 6y = 18 |÷3| --> x + 2y = 6
garis 2
5x + 5y = 5×5
5x + 5y = 25 |÷5| --> x + y = 5
eliminasi garis 1 dan 2 untuk mengetahui titik koordinat C
x + 2y = 6
x + y = 5
---------------- _
y = 1
x + y = 5
x + 1 = 5
x = 4

titik A (0,0)
f(0,0) = 5x+4y = 5(0) + 4(0) = 0
titik B (0,3)
f(0,3) = 5(0) + 4(3) = 12
titik C (4,1)
f(4,1) = 5(4) + 4(1) = 20 + 4 = 24
titik D (5,0)
f(5,0) = 5(5) + 4(0) = 25
nilai maksimum = 25 di titik D