tolong di jawag yah lks halaman 49 kelas 8 ,no 1,4,5

Persamaan Garis
SMP Kelas VIII

1.a] melalui (3, 5) dan (5, 9)
(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
(y - 5) / (9 - 5) = (x - 3) / (5 - 3)
(y - 5) / 4 = (x - 3) / 2
(y - 5) / 2 = (x - 3)
y -5 = 2(x - 3)
y - 5 = 2x - 6
y = 2x - 6 + 5
y = 2x - 1

1.b]melalui (-2, 1) dan (2, 4)
(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
(y - 1) / (4 - 1) = (x - (-2)) / (2 - (-2))
(y - 1) / 3 = (x + 2) / 4
4(y - 1)  = 3 (x + 2)
4y - 4 = 3x + 6
4y = 3x + 6 + 4
4y = 3x +10
3x - 4y = -10

1.c] melalui (3, 4) dan (7, -3)
(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
(y - 4) / (-3 - 4) = (x - 3) / (7 - 3)
(y - 4) / (-7) = (x - 3) / (4)
4 (y - 4) = -7 (x - 3)
4y - 16 = -7x + 21
4y = -7x + 21 + 16
4y = -7x + 37
7x + 4y = 37

2]
y = mx + c
m = gradien

y = 2x + 5
m = 2

tegak lurus, maka m1.m2 = -1
2 . m2 = -1
m2 = -1/2

gradien garis h adalah -1/2

3] melalui (-3, 5)
m = 2

(y - y1) = m(x - x1)
(y - 5) = 2(x - (-3))
y - 5 = 2(x + 3)
y - 5 = 2x + 6
y = 2x + 6 + 5
y = 2x + 11