bantu saya menjawab soal ini 15-19

jawab
15) m = 1/3 , (x1,y1)= 5,-3
y - y1 = m(x -x 1)
y + 3 = 1/3(x - 5)
3(y+3) = 1(x-5)
3y + 9 = x - 5
3y -x = -5-9
3y  - x = - 14

16) (x1,y1) = (5,-3)
m = -1/(-2/3) = 3/2
y - y1 = m(x - x1)
y + 3 = 3/2 (x - 5)
2(y+3)= 3(x - 5)
2y + 6 = 3x - 15
2y - 3x = - 21

17) (x1,y1)= (-2,-4) dan (x2,y2)= (-4,3)
(y-y1)/(y2-y1) = (x - x1)/(x2 -x 1)
(y+4)/(3+4) = (x +2)/(-4+2)
(y+4)/7 = (x+2) / -2
-2(y+4) = 7(x+2)
-2y -8 = 7x + 14
-2y - 7x = 22
2y + 7x = - 22

18) garis  melalui (3,4) dan (5,1) → m = (y2-y1)/(x2-x1)= (1-4)/(5-3)= -3/2
persamaan garis melalui (4,6) → y- y1 = m( x - x1)
y -6 = -3/2 (x - 4)
2(y-6) = -3(x-4)
2y -12 = - 3x + 12
2y +3x = 24


19) garis melalui (6,-4) sejajar garis melalui (-7.-4) dan (5,-5)
m = (-5 +4)/(5 +7) = -1/12
y - y1 = m (x - x1)
y + 4 = -1/12 (x - 6)
12(y + 4)= - 1(x - 6)
12y + 48 = -x + 6
12y  + x = - 38