Question

1. tentukan persamaan garis yang melalui titik
a. A (4,5) B (-3,2)
b. gradien (m) = -2 dan titik (-2,5)
2. tentukn persamaan garis yang melalui titik (7,4) dan sejajar garis 2x + 5y - 12 = -0

Answer 1

1a.
y-y1 / y2-y1 = x-x1 / x2-x1
y-5 / 2-5 = x-4 / -3-4
-7(y-5) = -3(x-4)
-7y+35 = -3x+12
3x-7y = 12-35
3x-7y = -23

1b.
y-y1 = m(x-x1)
y-5 = -2(x+2)
y-5 = -2x-4
y = -2x-4+5
y = -2x+1

2. (7,4) // 2x+5y-12 = 0
m1=m2=-a/b=-2/5
y-y1 = m(x-x1)
y-4 = -2/5(x-7)
y-4 = -2/5x + 14/5
y = -2/5x + 14/5 + 4
y = -2/5x + 34/5
5y = -2x + 34
2x+5y = 34