1) tentukan gradien yg melalui titik (2,7) dan (-5,9) 2) tentukan persamaan garis lurus yg melalui titik (5,3) dan (8,-5) 3) tentukan persamaan garis lurus yg m

1) m = ( y2 - y1 ) / ( x2 - x1 )
m = ( 9 - 7 ) / ( - 5 - 2 )
m = 2 / - 7
m = - 2/7

2) ( y - y1 ) / ( y2 - y1 ) = ( x - x1 ) / ( x2 - x1 )
( y - 3 ) / ( - 5 - 3 ) = ( x - 5 ) / ( 8 - 5 )
( y - 3 ) / - 8 = ( x - 5 ) / 3
3 ( y - 3 ) = - 8 ( x - 5 )
3y - 9 = - 8x + 40
3y + 8x = 40 + 9
3y + 8x = 49

3) 2x - 5y = 8
- 5y = - 2x + 8
m = -2/-5
m = 2/5
gradien saling sejajar,
m1 = m2 = 2/5
PGL :
y - y1 = m ( x - x1 )
y - 2 = 2/5 ( x - 7 )
y = 2/5 x - 14/5 + 2 ( × 5 )
5y = 2x - 14 + 10
5y - 2x = - 4

4) 4x + 2y = 4
2x - 10y = 2 |×2
maka
4x + 2y = 4
4x - 20y = 4
-------------------(-)
22y = 0
y = 0

4x + 2y = 4 |×5
2x - 10y = 2
maka
20x + 10y = 20
2x - 10y = 2
----------------------(+)
22x = 22
x = 1

hp = ( 1,0 )