To get the slope of an equation just differentiate it with respect to the independent variable.
d/dx (y = a)
dy/dx = d/dx (a)
{dy/dx = y'} a has no x term so {d/dx (a) = 0}
y' = 0 and...
Lines with equal slopes are parallel, because they are going the same direction. If the slope and the intercept are the same, the lines are coinciding, because they are on top of each other.
To answer this question we need to first get the slope of the line 5x-4y=9 by rearranging it in the form of y=mx+b: 5x-4y=9 4y=5x-9 y=(5/4)x-9/4 Since the slope of parallel lines are negative...