tolong dong bantuin, soalnya harus di kumpul sekarangg, sekalian cara penyelesaiannya tolong

a]
y = mx + c
m = gradien

y = -2/3x + 9
m = -2/3

b]
ax + by + c = 0
m = -a/b

Lx + 3y =0

m = -L/3

c]
4x + 2y + 6 = 0

m = - a/b
m = - 4/2
m = -2