santaclaus wrote:so, after the lesson I read, could I solve this by saying that -4 is the slope parallel?
Yes; parallel lines have the same slope.
santaclaus wrote:I don't know how to use the point (3 and 12) to think of an equation
Try using the methods explained and demonstrated in the lesson on straight-line equations (in the link provided earlier).
santaclaus wrote:i get y-12 = -4x+12 and then get y= -4x +24????
I think you did the following:. . . . .. . . . .. . . . .. . . . .. . . . .
If so, your method is fine!