Question

Tentukan persamaan garis garis berikut
1. garis melalui titik (-2, -4) dengan gradien -4
2. garis melalui titik (3, 4) dengan gradien ¹/₂
3. garis melalui titik (-2, 2) dengan gradien ¹/₄
4. garis melalui titik (4, -2) dengan gradien - ¹/₄

Answer 1

jawaban soal nomer 1
y -y1 = m ( x-x1)
y - (-4) = -4 ( x - (-2)
y + 4 = -4 ( x + 2)
y + 4 = -4x -8
   y    = -4x - 8-4
   y    = --4x -12

jawaban soal nomer 2
y -y1 = m ( x-x1)
y - 4 = 1/2 ( x - 3)
y -4  = 1/2x - 3/2 ----> sederhanakan X 2
2y - 8 = x - 3
2y  = x - 3 + 8
2y  = x + 5

jawaban soal nomer 3
y -y1 = m ( x-x1)
y - 2  = 1/4 ( x -(-2)
y -2  = 1/4 ( x+2)
y -2  = 1/4x + 1/2 ----> sederhanakan X 4
4y - 8 = x + 2
4y  = x + 2 + 8
4y  = x + 10

jawaban soal nomer 4
y -y1 = m ( x-x1)
y - (-2) = -1/4 ( x - 4)
y + 2  = -1/4x + 1
   y    = -1/4x + 1 - 2
   y    = -1/4x - 1 ---> sederhanakan X 4
  4y   = -x - 4

Answer 2

No 1
y-y1 = m(x-x1)
y+4 = -4(x+2)
y+4 = -4x-8
y = -4x-8-4
y = -4x-12

no 2
y-y1 = m(x-x1)
y-4 = 1/2(x-3)
y-4 = 1/2 x - 3/2
y = x/2 - 3/2 + 4
y = x/2 - 3/2 + 8/2
--------------------------- x 2
2y = x - 3 + 8
2y = x + 5

no 3
y-y1 = m(x-x1)
y-2 = 1/4(x+2)
y-2 = 1/4 x + 2/4
y = x/4 + 2/4 + 2
y = x/4 + 2/4 + 8/4
--------------------------- x 4
4y = x + 2 + 8
4y = x + 10

no 4
y-y1 = m(x-x1)
y+2 = -1/4(x-4)
y+2 = -1/4 x + 4/4
y = -x/4 + 4/4 - 2
y = -x/4 + 4/4 - 8/4
------------------------------- x 4
4y = -x + 4 - 8
4y = -x - 4