Respuesta :

y = mx + b
slope(m) = -3
(-1,-6)...x = -1 and y = -6
now we sub and find b, the y int
-6 = -3(-1) + b
-6 = 3 + b
-6 - 3 = b
-9 = b

y = -3x - 9...add 3x to both sides
3x + y = -9 <== standard form