Y=mx+b ....? - Page 1

Site Notices

TNVC Partners With Envision Technology - MARS Rangefinder Family, MARS-Lc!

Posted: 8/3/2017 3:54:35 PM EDT

Can some explain to me how to solve a linear graph problem that goes like this....

Which of the following pairs lie on the
line whos equation is 3x-y=2?

(3,-2) and (1,5)

(2,4) and (3,7)

(2,4) and (1,5)

(2,-2) and (1,5)

(3,7) and (3,-2)

Posted: 8/3/2017 4:03:36 PM EDT

[#1]

Quoted:
Can some explain to me how to solve a linear graph problem that goes like this....

Which of the following pairs lie on the
line whos equation is 3x-y=2?

(3,-2) and (1,5)

(2,4) and (3,7)

(2,4) and (1,5)

(2,-2) and (1,5)

(3,7) and (3,-2)

View Quote

Solve for y, plot points.

y=3x-2

Slope is 3, y intercept is - 2

ETA You could also just start plugging the given pairs into the equation and see which work.

Posted: 8/3/2017 4:07:39 PM EDT

[#2]

Thread title is racist.

Posted: 8/3/2017 4:17:24 PM EDT

[#3]

Since these are X,Y coordinates, the easiest way is to plug in the numbers to see which give a true outcome.

The answer should be (2,4) and (3,7)

3X-Y=2
3(2)-4=2
6-4=2
2=2

Now you try it with the other coordinate.

Posted: 8/3/2017 4:19:35 PM EDT

[#4]

I just learned that if you type "graph y=3x-2" into Google it will graph it for you.

Posted: 8/3/2017 4:20:32 PM EDT

[#5]

baleeted

Posted: 8/3/2017 4:20:40 PM EDT

[#6]

Quote History

Quoted:
Thread title is racist.

View Quote

I was expecting a video of a guy walking on a bridge built by 3 British guys

Posted: 8/3/2017 4:22:45 PM EDT

[#7]

Thanks guys. I appreciate it!
Im gonna play with this some more today. I will be back if Im too tarded to figure them without more help!

Also didnt know math equations are now racist?

Posted: 8/3/2017 4:23:36 PM EDT

[#8]

Quote History

Quoted:

Not "should be", it is.

But you should show him how to get the answer, not give it to him.

View Quote

I was in the middle of editing my post to do just that when you posted this.

Posted: 8/3/2017 4:23:46 PM EDT

[#9]

Without even doing math I forgot decades ago, this one is pretty easy. Just a quick glance at the combinations shows that only one set can possibly have a slope of (3).

Posted: 8/3/2017 4:25:02 PM EDT

[#10]

http://www.wolframalpha.com/

The pro version gives you the step-by-step answers on how to solve the problem.

Posted: 8/3/2017 4:26:02 PM EDT

[#11]

Just finished 4 credit intermediate algebra course....in a 6 week summer session. Your title gave me flashbacks.

Posted: 8/3/2017 5:27:01 PM EDT

[#12]

Quote History

Quoted:
Just finished 4 credit intermediate algebra course....in a 6 week summer session. Your title gave me flashbacks.

View Quote

Nice

Sounds like the boat I'm currently riding in.

Thanks again, you guys are AWESOME!

Glad I know where the smart fellers hang out on arf!

Posted: 8/3/2017 5:31:54 PM EDT

[#13]

Quote History

Quoted:

Solve for y, plot points.

y=3x-2

Slope is 3, y intercept is - 2

ETA You could also just start plugging the given pairs into the equation and see which work.

View Quote

Plug and jug in excel.

Done in 1 minute. Essentially zero chance for error.

Posted: 8/3/2017 6:25:38 PM EDT

[#14]

So essentially I need to just plug all numbers and see which one works..

Like find slope, y inercept and only one answer will work.

Ok I got it now!!!!!!

Posted: 8/3/2017 7:05:28 PM EDT

[#15]

Quote History

Quoted:
So essentially I need to just plug all numbers and see which one works..

Like find slope, y inercept and only one answer will work.

Ok I got it now!!!!!!

View Quote

If you want to draw the line, first put the equation in y equals m times X plus b form. B is the Y intercept so you know the first point to plot is zero, negative 2. M is the slope, or the amount the line Rises for every space forward. Starting with 0, negative 2 the next point would be one, one and after that too, for. From there you can just draw a line between the three points and see how it continues both to the right and to the left of origin. Without solving for y equals MX plus b form, just plug in the given points to see which make the equation true. While the latter method is foolproof, the first method gives you a better sense working with linear equations.

Forgive the formatting above, it was dictated into my phone.

Posted: 8/4/2017 7:43:45 AM EDT

[#16]

Quote History

Quoted:

Also didnt know math equations are now racist?

View Quote

Sorry about that, didn't realise it wasn't GD.

Posted: 8/4/2017 8:28:49 AM EDT

[#17]

Quote History

Quoted:
Without even doing math I forgot decades ago, this one is pretty easy. Just a quick glance at the combinations shows that only one set can possibly have a slope of (3).

View Quote

This. First check your slope. That will eliminate a lot.

Slope=(y2-y1)/(x2-x1)

Posted: 8/4/2017 8:32:18 AM EDT

[#18]

Quote History

Quoted:
Also didnt know math equations are now racist?

View Quote

Well what's the name of the equation you posted?

(It's a math joke told to me by the Korean dude that sat behind me in high school algebra - "don't intercept me, white devil, we just want to be left alone".)

Posted: 8/4/2017 12:04:22 PM EDT

[#19]

Quote History

Quoted:
This. First check your slope. That will eliminate a lot.

Slope=(y2-y1)/(x2-x1)

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:
Without even doing math I forgot decades ago, this one is pretty easy. Just a quick glance at the combinations shows that only one set can possibly have a slope of (3).

This. First check your slope. That will eliminate a lot.

Slope=(y2-y1)/(x2-x1)

Plug the points into the equation and see if it is true.

The left side equals the right side.

Posted: 8/4/2017 12:54:46 PM EDT

[#20]

Lots of ways to solve this, but the way I'd do it is to solve for y...

3x-y=2

y=3x-2

Then start plugging in the x values and validating the y value matches the expected value:

(3,-2) and (1,5) 3(3)-2=7, this one is out

(2,4) and (3,7) 3(2)-2=4, good. 3(3)-2=7, good. Winner Winner.

(2,4) and (1,5) 3(2)-2=4, good. 3(1)-2=1, nope.

(2,-2) and (1,5) 3(2)-2=4, nope. 3(1)-2=1, nope.

(3,7) and (3,-2) Pretty sure a vertical line won't work

Posted: 8/28/2022 2:01:03 AM EDT

[#21]

[Deleted]

Posted: 8/28/2022 3:32:14 AM EDT

[#22]

Have you used Desmos.com , for graphing.? The different colors for each line are good for comparing.

Posted: 8/28/2022 12:08:17 PM EDT

[#23]

Quote History

Quoted:
http://www.wolframalpha.com/

The pro version gives you the step-by-step answers on how to solve the problem.

View Quote

If you buy the Wolfram Alpha smartphone app, it's a one-time purchase for about $3-4 and it will do the step by step process for you. And you don't have to pay for an ongoing Pro subscription.

Posted: 8/28/2022 12:48:22 PM EDT

[#24]

Are there really adults that can’t solve this problem?

Posted: 8/28/2022 12:59:37 PM EDT

[#25]

I would start with x=0.
That gets you your first coordinate.
Then try x=1.
That gets you the next intersecting slope point on the graph (assuming only whole numbers).

Posted: 10/2/2022 11:56:23 AM EDT

[#26]

Quote History

Quoted:
Are there really adults that can’t solve this problem?

View Quote

I last took a geometry course in 1995, and any sort of algebra in 2000.

So, yes.

Which is why I popped into this thread. I've also ordered high school level algebra and geometry workbooks from Amazon because I'm kinda ashamed I can't high school math.

Posted: 4/28/2023 1:39:19 AM EDT

[#27]

I like this one:

m = (y2-y1)/(x2-x1)

y = y0 +m(x-x0)

substituting yields -

y = y0 +((y2-y1)/(x2-x1))*(x-x0)

I think these three (especially the last one) tell you everything you need to know about your data pairs.

[ARCHIVED THREAD] - Y=mx+b ....?

General » Math And Science

Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us