Which lines are parallel?
y=-3x+1
-3x+y=5
2y=-6x+12
The equation of a straight line is usually written in Slope-Intercept Form :
y = mx + b
Rewrite second and third equations:
-3 x + y = 5
y = 3 x + 5
( Slope = 3 )
2 y = -6 x + 12 Divide both sides with 2
y = -3 x + 6
( Slope = - 3 )
Parallel lines have the same slope.
Lines:
y = - 3 x + 1
and
2 y = -6 x + 12 = -3 x + 6
are parallel.