Gradien garis k = (1-0)/(0-2) = - 1/2. misal gradien k adalah m1 = -1/2 gradien garis l, misal m2, maja m1.m2 = -1 -1/2.m2 = -1 => m2 = 2 melalui (2, 0) y - y1 = m (x - x1) y - 0 = 2 (x -2) y = 2x -4 2) misal biaya parkir mobil x dan motor y, maka 3x + 5y = 17.000,-...(1) 4x + 2y = 18.000,- => 2x + y = 9.000,-..(2) eliminasi x, maka (1)×2 dan (2)×3 6x + 10y = 34.000,- 6x + 3y = 27.000,- -------------------------- - 7y = 7.000 y = 1.000,- 2x + y = 9000 2x + 1.000 = 9.000 2x = 8.000,- x = 4.000,- f(x,y)=> f (20,30) = 20 × 4.000 + 30 × 1.000,- = 80.000 + 30.000 = Rp 110.000,-
Verified answer
Gradien garis k = (1-0)/(0-2) = - 1/2. misal gradien k adalah m1 = -1/2gradien garis l, misal m2, maja m1.m2 = -1
-1/2.m2 = -1 => m2 = 2 melalui (2, 0)
y - y1 = m (x - x1)
y - 0 = 2 (x -2)
y = 2x -4
2) misal biaya parkir mobil x dan motor y, maka
3x + 5y = 17.000,-...(1)
4x + 2y = 18.000,- => 2x + y = 9.000,-..(2)
eliminasi x, maka (1)×2 dan (2)×3
6x + 10y = 34.000,-
6x + 3y = 27.000,-
-------------------------- -
7y = 7.000
y = 1.000,-
2x + y = 9000
2x + 1.000 = 9.000
2x = 8.000,-
x = 4.000,-
f(x,y)=> f (20,30)
= 20 × 4.000 + 30 × 1.000,-
= 80.000 + 30.000
= Rp 110.000,-
. .