tentukan persamaan garis yang melalui titik berikut: a. (-6,-5) dan (0,11) b. (7,-3) dan (12,9) c. (3,10) dan (-1,2) d. (0,4) dan (-3,-1) tolong jwb ya

Jawab :

1) melalui titik (-6,-5) dan (0,11)

y2 - y1/ x2 - x1 = 11 - (-5)/ 0 - (-6) = 16/6

y - y1 = m(x - x1)
y - (-5) = 16/6(x - (-6))
y + 5 = 16/6(x + 6)
y + 5 = 16/6x - 16/6 x 6
y + 5 = 16/6x - 96/6 
--------------------------------- x 6
6 . y + 5 . 6 = 16/6x . 6 - 96/6 . 6

6y + 30 = 16x - 96
6y + 30 - 16x + 96
6y - 16x + 126 = 0
-16x + 6y + 126 = 0 => ax + by + c = 0

2) melalui titik (7,-3) dan (12,9)

y2 - y1/ x2 - x1 = 9 - (-3)/ 12 - 7 = 12/5

y - y1 = m(x - x1)
y - (-3) = 12/5(x -7)
y + 3 = 12/5(x - 7)
y + 3 = 12/5x - 12/5 x 7
y + 3 = 12/5x - 84/5 
----------------------------------- x 5
5 . y + 3 . 5 = 12/5x . 5 - 84/5 . 5

5y + 15 = 12x - 84
5y + 15 - 12x + 84 = 0
5y - 12x + 99 = 0
-12x + 5y + 99 = 0 => ax + by + c = 0

3) melalui titik (3,10) dan (-1,2)

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

y - y1 = m(x - x1)
y - 10 = 8/4(x - 3) 
y - 10 = 8/4x - 8/4 x 3
y - 10 = 8/4x - 24/4
-------------------------------- x 4
4. y - 10 . 4 = 8/4x . 4 - 24/4 . 4 

4y - 40 = 8x - 24
4y - 40 - 8x + 24 = 0
4y - 8x - 16 = 0
-8x + 4y - 16 = 0 => ax + by + c = 0

4) melalui titik (0,4) dan (-3,-1)

y2 - y1/ x2 - x1 = (-1) - 4/ (-3) - 0 = -5/-3 = 5/3

y - y1 = m(x - x1)
y - 4 = 5/3(x - 0)
y - 4 = 5/3x - 5/3 x 0
y - 4 = 5/3 - 0/3
---------------------------- x 3
3. y - 4 . 3 = 5/3x . 3 - 0/3 . 3

3y - 12 = 5x - 0
3y - 12 - 5x + 0 = 0
3y - 5x - 12 = 0
-5x + 3x - 12 = 0 => ax + by + c = 0