persama garis gambar titik 5,10 3,15

( y - y1 ) / ( y2 - y1 ) = ( x - x1 ) / ( x2 - x1)
( y - 10) / ( 15 - 10) = ( x - 5) / ( 3 - 5)
( y - 10) / 5 = ( x - 5 ) / ( - 2)
- 2( y - 10) = 5 ( x - 5)
- 2y + 20 = 5x - 25
- 2y - 5x = - 25 - 20
- 2y - 5x = - 45
2y + 5x = 45