for what value of a are the graphs of 6y = -2x + 4 and 2y = ax - 5 parallel? perpendicular?

Question

the graphs are parallel when a=

the graphs are perpendicular when a=

Answer 1

y=(-2/6)x + 4 sleope = -2/6 = -1/3, the coefficient of the x term when the equation is solved for y

y=(a/2)x -5/1 is parallel when a/2 =-1/3, when a = -2/3

It's perpendicular when a/2 =3 or a = 6

they're parallel when they have the same slope, and perpendicular when their slopes are negative inverses of each other.