# How do you tell whether the graphs of the pair of equations is parallel, perpendicular or neither for 4x+3y=6 and 3x-4y=7?

Jul 12, 2015

$r \setminus \bot s$
$r : y = \frac{6 - 4 x}{3} = - \frac{4}{3} x + 2$
$s : \frac{3 x - 7}{4} = y = \frac{3}{4} x - \frac{7}{4}$
tan (90º - \theta) = - 1 / tan \theta