1. tentukan persamaan garis dg gradien 2 dan melalui tittik berikut! a. (3,-4) b. (-2,-5) c. (5,0) 2.tentukan persamaan garis dan gradien yng mala

1. a. m = 2
x1 =3
y1 = -4
=> (y-y1) = m(x-x1)
(y-(-4)) = 2 (x-3)
(y+4) = 2x-6
y = 2x -6-4
y = 2x -10
b. x1 = -2
y1 = -5
=> (y-y1) = m(x-x1)
(y-(-5)) = 2 (x-(-2))
y+5 = 2x + 4
y = 2x + 4 -5
y = 2x - 1
c. x1= 5
y1 = 0
=> (y-y1) = m(x-x1)
(y-0) = 2 (x - 5)
y = 2x -10
2. Persamaan garis & gradien melalui 2 titik:
a. (12,8) & (4,5)
Gradien:
m = (y1-y2) / (x1-x2)
= 8-5 / 12-4
= 3 / 8
Persamaan:
(y-y1) = m (x-x1)
(y-8) = 3/8 (x-12)
8(y-8) = 3 (x-12)
8y-64 = 3x-36
8y = 3x-36+64
y = 3x+28 / 8
y = 3/8 x + 17/2
Atau 8y =3x+17
b. (-1,5 ) dan (-3,2)
=> gradien
m = (y1-y2) / (x1-x2)
= 5-2 / -1-(-3)
= 3/2
=> persamaan
(y-y1) = m (x-x1)
(y-5) = 3/2 (x-(-1)
y-5 = 3/2x + 3/2
y = 3/2x + 3/2 + 5
y = 3/2x + 13/2
Atau 2y = 3x+13