Jawabanmu

2014-05-05T20:56:11+07:00
2x + y = 12+3
tergantung pilihan 
y = -2x+15
2x = -y +15
2(4) + 3 + 7 = 0
gimana -__-
2x + y + 2(4) + 3
2x + y = 8 + 3
loh kok gitu caranya,,,?
2014-05-05T20:59:04+07:00
2x+y+7=0
y=-2x-7
gradien= -2

y-y₁=m (x-x₁)
y-3= -2 (x-4)
y-3=-2x+8
y=-2 x +8
     -3
-3y=-2x+8
2x-3y-8=0