ShmoopTube

00:02

For a good time, solve this shmoopy question...

00:05

Which of these three lines are parallel?

00:08

Here are your options....

00:12

Alright we know that when the slopes are the same

00:14

the lines are parallel. So we can bring back our old friend Y equals MX plus B here.

00:19

The key activity in this problem is to just reconstitute the equations to be in

00:24

standard line form.

00:25

For equation one its already in that form and the slope is -3.

00:29

For equation 2

00:33

let's start by subtracting 6x from both sides and we have

00:36

-2y equals -6x plus 4

00:39

multiply both sides by -1 to get 2y equal 6x -4

00:44

we divide both sides by 2 to get y equals 3x -2

00:48

So the slope is positive 3. For equation three we start by adding 9x to both

00:55

sides to get 3y equals 9x - 1

00:58

Now get rid the 3 in the 3y by dividing both sides by 3 to get y

01:03

equals 3x -1 by three. So the slope here is 3.

01:08

We have one equation with slope -3

01:11

and two with positive 3. So 2 and 3 are parallel.

01:16

Option C is our answer.

Full Transcript