is 9x+3y=12; 27x+9y=40 parallel, perpendicular, or neither?

We know that two lines are parallel if they have the same slope (and they are distinct). When the lines are in general form we'll use the formula m=-B/A to find their slopes with 
 

 


first line: m=-3/9=-1/3 
second line: m=-9/27=-1/3 

these lines have the same slope and since we know that they are not the same line because 
 


they must be parallel 

:)