How do you determine if the lines #-12x+9y=15# and #-4x+3y=5# are paralle , perpendicular or neither?
I would look at the slope of the lines represented by these equations (it representes the inclination of the lines):
first write them isolating
The slope is the coeficient of
You can have:
1) same slope=parallel lines;
2)slope1=-1/slope2 =perpendicular lines;
In this case they are parallel (and coincident).