teman.. tolong dibantu ya Tentukan persamaan garis yang melalui titik : a. (3, -5) dan (-2, -3) b. (-1, 10) dan (3, -8) c. (0, 3) dan (4, 9) d. (-2, 7) dan (4,

Jawab :

1) y2 - y1/ x2 - x1 = (-3) - (-5)/ (-2) - 3 = 3/-5 = - 3/5

y - y1 = m(x - x1)
y - (-5) = - 3/5(x - 3)
y + 5 = - 3/5x + 3/5 x 3
y + 5 = - 3/5 + 9/5
----------------------------- x 5
5.y + 5 . 5 = - 3/5x . 5 + 9/5 . 5

5y + 25 = -3x + 9
5y + 25 + 3x - 9 = 0
5y + 3x + 16 = 0
3x + 5y + 16 = 0 => ax + by + c = 0 

2) y2 - y1/ x2 - x1 = (-8) - 10/ 3 - (-1) = -18/4

y - y1 = m(x - x1)
y - 10 = -18/4(x - (-1))
y - 10 = -18/4x + 18/4 x 1
y - 10 = -18/4x + 18/4
----------------------------------- x 4
4.y - 10 . 4 = -18/4x . 4 + 18/4 . 4

4y - 40 = -18x + 18
4y - 40 = + 18x - 18 = 0
4y + 18x - 58 = 0
18x + 4y - 58 = 0 => ax + by + c = 0

3) y2 - y1/ x2 - x1 = 9 - 3/ 4  - 0 = 6/4

y - y1 = m(x - x1)
y - 3 = 6/4(x - 0)
y - 3 = 6/4x - 6/4 x 0
y - 3 = 6/4x - 0/4
-------------------------- x 4
4.y - 3 . 4 = 6/4x . 4 - 0/4 . 4

4y - 12 = 6x - 0
4y - 12 - 6x + 0 = 0
4y - 6x - 12 = 0
-6x + 4y - 12 = 0 => ax + by + c = 0 

4) y2 - y1/ x2 - x1 = (-5) - 7/ 4 - (-2) = -12/6 = -2

y - y1 = m(x - x1)
y - 7 = -2(x - (-2))
y - 7 = -2(x + 2)
y - 7 = -2x + 2
y = -2x + 2 + 7
y = -2x + 9 => mx + c