How do you find the slope of a line parallel to the graph of each question y=3x-8?

1 Answer
Apr 1, 2015

Parallel lines have the same slope. Think slope as the angle between the line and the x-axis. So it makes sense that the slopes have to be equal.

#y# is the line with a slope of #3#.

The standart form formula is #ax+by=c#.

The slope is: #-a/b#

If you can't remember this, you can calculate the slope by selecting two random points on the line #y#.

#A = (0,-8)#
#B = (1,-5)#

The slope is: #(-8 - (-5))/(0-1) = 3#

So any line with slope #3# is parallel to the line #y# (accept #y# itself, it is called coincident line)

So we can say this:

A line is parallel to another if and only if their slopes are equal.