1. Persamaan garis yg melalui titik (-2,5) dan titik (8,-1) adalah...... 2. Persamaan garis yang melalui (5,4) dan sejajar dengan garis yang persamaanya 5y-3x =

1) ( y - y1 ) / ( y2 - y1 ) = ( x - x1 ) / ( x2 - x1 )
( y - 5 ) / ( - 1 - 5 ) = ( x + 2 ) / ( 8 + 2 )
( y - 5 ) / - 6 = ( x + 2 ) / 10
10 ( y - 5 ) = - 6 ( x + 2 )
10y - 50 = - 6x - 12
10y + 6x = - 12 + 50
10y + 6x = 38 ( disederhanakan)
5y + 3x = 19

2) 5y - 3x = 2
5y = 3x + 2
m = 3/5
sejajar m1 = m2 = 3/5
pers garis
y - y1 = m ( x - x1 )
y - 4 = 3/5 ( x - 5 )
y = 3/5 x - 3 + 4
y = 3/5 x + 1 ( dikali 5 )
5y = 3x + 5
5y - 3x = 5

Kelas 8 Matematika
Bab Persamaan Garis

1] (y - y1)/(y2 - y1) = (x - x1)/(x2 - x1)
(y - 5)/(-1 - 5) = (x + 2)/(8 + 2)
(y - 5)/(-6) = (x + 2)/10
10(y - 5) = (-6) (x + 2)
10y - 50 = -6x - 12
6x + 10y = 50 - 12
6x + 10y = 38
3x + 5y = 19

2] ax + by = c, sejajar, (p, q)
ax + by = ap + bq

-3x + 5y = 2, sejajar, (5, 4)
-3x + 5y = -3 . 5 + 5 . 4
5y = 3x -15 + 20
y = (3/5) x + (5/5)
y = (3/5) x + 1