Question

Are the following lines parallel, perpendicular, or neither?

3x + 5y = 40
11 - y = 3/5x

Answer 1

@trish, ask yourself the following question: Are the slopes of both lines the same or are they negative reciprocals of one another?

Answer 2

@hero yes they are

Answer 3

@hero oh so it's perpendicular

Answer 4

@trish, Why do you think they are perpendicular?

Answer 5

And can you please verify your email? You will not be able to use the messaging system unless you do so.

Answer 6

@hero it's not sending me an email

Answer 7

@hero I thought they were perpendicular because of the slope being flipped first its 3,5. Then in the next line it has 3/5

Answer 8

You're not receiving any emails because you have not verified the initial email that was sent to you.

Answer 9

You have to check both your spam and your inbox to find it.

Answer 10

@hero ok I verified it so about the question am I right

Answer 11

Okay so here are the two lines:

3x + 5y = 40
11 - y = (3/5)x

Be sure to use parentheses so that people do not interpret \(\dfrac{3}{5}x\) to mean \(\dfrac{3}{5x}\).

Answer 12

@Hero so it is perpendicular?

Answer 13

So the thing is if you multiply both sides of the 2nd equation by 5 you end up with 55 - 5y = 3x

Then adding 5y to both sides you get 3x + 5y = 55 which shows that the lines both have the same slope.

Answer 14

are they parallel?

Answer 15

What are your thoughts regarding this? Do you understand what I did?

Answer 16

@hero no

Answer 17

So the 2nd equation gave you was \(11 - y = \dfrac{3}{5}x\) correct?

Answer 18

@trish

Answer 19

yes @hero

Answer 20

Okay so what happens if you try multiplying both sides by 5?

Answer 21

that cancels out and it leaves you with 55-5y=3x

Answer 22

@Hero

Answer 23

Yes correct. And then as I said, when you add 5y to both sides, you end up with
3x + 5y = 55. Compare that with 3x + 5y = 40.

Answer 24

@hero so that means it's neither

Answer 25

Have you tried graphing them on http://www.desmos.com?

Answer 26

@hero I'll try

Answer 27

:D

Answer 28

@Hero oh ok they're parallel

Answer 29

@hero thanks for your help

Answer 30

Yes, parallel correct.

Answer 31

@trish