20]

(-6 , 1) dan (3 , 5)

x1 = -6 dan x2 = 3

y1 = 1 dan y2 = 5

m = (y2 - y1)/(x2 - x1)

m = (5 - 1)/(3 - (-6))

m = (5 - 1)/(3 + 6)

m = 4/9 (C)

21]

(-2 , -4) dan (7 , -6)

x1 = -2 dan x2 = 7

y1 = -4 dan y2 = -6

(y - y1)/(y2 - y1) = (x - x1)/(x2 - x1)

(y - (-4))/(-6 - (-4)) = (x - (-2))/(7 - (-2))

(y + 4)/(-6 + 4) = (x + 2)/(7 + 2)

(y + 4)/(-2) = (x + 2)/9

9(y + 4) = -2(x + 2)

9y + 36 = -2x - 4

2x + 9y = -4 - 36

2x + 9y = -40 (A)

22]

garis k :

(-2 , 1) dan (2 , 4)

x1 = -2 dan x2 = 2

y1 = 1 dan y2 = 4

m1 = (y2 - y1)/(x2 - x1)

m1 = (4 - 1)/(2 - (-2))

m1 = (4 - 1)/(2 + 2)

m1 = 3/4

karena sejajar , maka :

m2 = m1 = 3/4

melalui titik (8 , 5) --> x3 = 8 dan y3 = 5

garis l :

y - y3 = m2(x - x3)

y - 5 = 3/4(x - 8)

y - 5 = (3/4)x - 6

y = (3/4)x - 6 + 5

y = (3/4)x - 1 (B)