Math Problem

cqpkytty • 23 October 2012 at 9:02 PM

@twilight_raptor
?

Um...no...
Um. I don't think so...

mairbear • 23 October 2012 at 9:06 PM

LOL This annoyed me so I went and googled it xD

Standard form of a linear equation is actually:

Ax + By = C

*laughs sheepishly* 😋

So errm rearranging her equation you get:

1x -1y = -3/5

A = 1
B = -1
C = -3/5

*pretends to be mod* Topic closed 8D

P.S. y = mx + b is the slope-intercept form of a linear equation~

twilight_raptor • 23 October 2012 at 9:06 PM

@mairbear C should not be a fraction or decimal 😸

cqpkytty • 23 October 2012 at 9:12 PM

Oh 😋


Hm...
1x-1y=-3/5
5x-5y=-3?
A=5
B=5
C=-3
?

2elle2 • 23 October 2012 at 9:40 PM

@puppyloverlauren
x+3/5= y

Hmm.... you want it in standard form? I thought you wanted to know how to graph it xD

We want to figure out what x+3/5=y is in standard form.

Standard form is the following form:
ax+by=c

First, you multiply both sides of x+3/5=y, by 5. It would look something like this:

5(x+3/5)=(y)5

Now the equation is:

5x+3=5y

You currently have 5x+3=5y. Subtract both sides of the equation by 5y:

5x+3=5y
-5y -5y
5x+3-5y=0

Next, subtract both sides by 3:

5x+3-5y=0
-3 -3
5x-5y=-3

The equation in standard form is 5x-5y=-3. This means that a=5, b=-5, and c=-3. Remember, the standard form is ax+by=c!

(:

~~~The following is irrevelant to your question, I already typed it so I'm keeping it here xD~~~

The equation is x+3/5= y, which is actually the same as y=x+3/5. This equation is in the form y=mx+b.
m is the slope of the line, and b is the y-intercept.
In this equation, the slope is 1 and the y-intercept is 3/5.
To graph it, first find the point 3/5 on the y-axis.
Next, because we know the slope of the line is 1, go up 1 point and to the right 1 point from the point (0,3/5) on the graph. You can also go down one and left one. The points you should end up with are (2,2 3/5), (1,1 3/5), (0, 3/5), (-1,-1 3/5), and (-2, -2 3/5). Of course there are infinitely more points on the line, I'm just listing a few.
Now trace the points and you should get a straight line. You can also do it a different way, I am just explaining one.
~~~

puppyloverlauren • 23 October 2012 at 9:52 PM

@2elle2 @twilight_raptor @mairbear

sorry, i went out eating... the answer in the book says:
a=1
b=-5
c=-3

how do you solve it like this then?

twilight_raptor • 23 October 2012 at 9:55 PM

@puppyloverlauren really? O.o well I dunno seems like A is the only one that doesn't match with our answers.. are you sure?

puppyloverlauren • 23 October 2012 at 9:56 PM

@twilight_raptor

yeah it might be a typo because the textbook sometimes have typos

twilight_raptor • 23 October 2012 at 9:56 PM

@puppyloverlauren oh... 😋

puppyloverlauren • 23 October 2012 at 9:57 PM

@twilight_raptor

no the book says this:
x-5y=-3

A=1
B=-5
C=-3
non horizontal, non vertical line

mairbear • 23 October 2012 at 9:58 PM

@puppyloverlauren
Well either the question or the answer is wrong then 😋

twilight_raptor • 23 October 2012 at 10:00 PM

x-5y=-3

thats the answer to the question?
@puppyloverlauren

I don't think that works out...

puppyloverlauren • 23 October 2012 at 10:07 PM

@twilight_raptor

yeah i'll just leave it blank ._.

sunshinecat • 23 October 2012 at 10:07 PM

x-5y=-3 does work as a rearrangement of x+3/5=y.

We don't do this standard form stuff in NZ, but if you just want to turn the first equation into the second it works.

If the way it works is just getting x and y on one side, with the number on the other, then it's correct.

x+3/5=y
x+3=5y
x-5y+3=0
x-5y =-3

2elle2 • 23 October 2012 at 10:24 PM

@sunshinecat

No it does not work as a rearrangement of x+3/5=y. At least when I try it it doesn't....

This is what you did:

x+3/5=y
x+3=5y <--here is the problem.
x-5y+3=0
x-5y =-3

x+3/5=y does not equal x+3=5y.

To get rid of the fraction 3/5 in the original equation, you have to multiply the equation by 5. What you did was you multiplied 3/5 and y by 5, but you forgot to multiply the x.
I think this is what you did:
5(x+3/5)=(y)5
but you forgot to multiply the whole equation by 5.
You have to multiply everything by 5, not just 3/5 and y.
My math teacher(s) keep on reminding us: the golden rule is "Do unto one side of an equation as you do unto the other side." So basically when you do something, for example multiply a quantity to one side of an equation, you do the same thing, in this case multiply the same quantity, to the other side.
I hope that made sense xD

schusteralex2 • 23 October 2012 at 10:30 PM

@puppyloverlauren Here's what I got: 5x-5y=-3 😊

whitefall • 23 October 2012 at 10:41 PM

x+3/5=y
Standard Form: Ax + By =C
x - y = -3/5
5(x - y) = 5(-3/5) <~ Multiplying 5 to both sides. need to get rid of the fraction because A, B and C must be integers.
5x - 5y =-3
A= 5
B = -5
C =-3

Ehhh. That's the closest I could get to the real answer in your textbook. 😸


Could you tell me what the instructions said EXACTLY in your book/worksheet?

sunshinecat • 23 October 2012 at 10:46 PM

@2elle2 I assumed that the 3/5 wasn't a fraction, but rather that it was

x+3
-------
5

So, the line was over the x+3. I just thought it was because you can't type out those kind of divisions well on the internet.

If it's that way (which is likely because my answer and the book answers match up) then it works.

I didn't 'forget' to do anything, I just interpreted the question in a different way so that it worked.

ljacks • 24 October 2012 at 12:02 AM

@puppyloverlauren

Whooo, I think I got it! Even if you did not ask me, unanswered math problems bug me. Hopefully I am not too late!

Here is another way you can look at the problem:
x + 3 = y
- -
5 5

So first you would multiply by 5 on both sides to neaten everything to get:

x + 3 = 5y

Now it look like a regular problem. So subtract 3 from both sides to get:

x = 5y - 3

Then subtract 5y from both sides to get this:

x - 5y = -3

A = 1
B = -5
C= -3

Please let me know if this is correct!

Edit: I notice after submitting that the spacing doesn't quite match in my interpretation at the top, it would read x over 5 plus 3 over 5 equals y.

puppyloverlauren • 24 October 2012 at 7:17 PM

@ljacks

thank you ^^ topic closed!