Persamaan garis lurus yang melalui titik (0,-5) dan (-1,2) adlh....

diket :
x1 = 0 , y1 = -5
x2 = -1 , y2 = 2
maka,
pers.grs.lurus melalui ttk.(0,5) dan (-1,2) :
y-y1 / y2-y1 = x-x1 / x2-x1
y-(-5) / 2-(-5) = x-0 / -1-0
y+5 / 2+5 = x/-1
y+5 / 7 = x/-1
7x = -1(y+5)
7x = -y-5
7x+y+5 = 0

Jawab :

y2 - y1/ x2 - x1 = 2 - (-5)/ (-1) - 0 = 7/-1 = - 7/1

y - y1 = m(x- x1) 
y - (-5) = - 7/1(x - 0)
y + 5 = - 7/1x + 7/1 x 0
y + 5 = - 7/1x + 0/1
----------------------------- x 1
1 . y + 5 . 1 = - 7/1x . 1 + 0/1 . 1

1y + 5 = -7x + 0 
1y + 5 + 7x - 0 = 0
1y + 7x + 5 = 0
7x + 1y + 5 = 0 => ax + by + c = 0