Tulislah peraamaan garis m=1/2 c=(0,-1)

m = 1/2
c = ( 0, -1 )
persamaan garis
y - y1 = m ( x - x1 )
y - ( -1 ) = 1/2 ( x - 0 )
y + 1  = 1/2x
 y      = 1/2x - 1

Dik
m = 1/2
c = (0, -1) => ( x1 , y1)

pers. Garisnya
y - y1    = m (x - x1)
y - (-1)  = 1/2 (x - 0)
y + 1 = 1/2 x       kalikan 2
2y + 2 = x
x - 2y - 2 = 0 




semoga membantu ^_^