Omfg. Homework help, PL0X.

[Jakuza]

Im not really the one to ask, but this is pretty complicated to me.


You guys know about the 'system of equations' and the 3 ways to solving them, right?...

1.graphing
2.substitution
3.elimination


Well I need some help with substitution..


When its something like this...

y=2x

and

y=3x-2

or

y=x

y=2x-4

What exactly do you do?


Yeah, I took notes on it in school, but its still pretty fuzzy in my head.
Help is much apreciated. =/

[laughingman112]

Im not really the one to ask, but this is pretty complicated to me.


You guys know about the 'system of equations' and the 3 ways to solving them, right?...

1.graphing
2.substitution
3.elimination


Well I need some help with substitution..


When its something like this...

y=2x

and

y=3x-2

or

y=x

y=2x-4

What exactly do you do?


Yeah, I took notes on it in school, but its still pretty fuzzy in my head.
Help is much apreciated. =/

O my god, this is easy. I can't explain it by typing but what grade are you in? I learn this in 7th grade.

[KCBlack]

Im not really the one to ask, but this is pretty complicated to me.


You guys know about the 'system of equations' and the 3 ways to solving them, right?...

1.graphing
2.substitution
3.elimination


Well I need some help with substitution..


When its something like this...

y=2x

and

y=3x-2

or

y=x

y=2x-4

What exactly do you do?


Yeah, I took notes on it in school, but its still pretty fuzzy in my head.
Help is much apreciated. =/

What grade you in? Anyway, I just got a 98 in advanced pre-al, so maybe I can help. :P
We just did this shit last week. We'll use this.
y=x

y=2x-4

So take y=x for example, or x=y. Now, if x=y, let's substitute in for the x variable in the second equation. So y=2(y)-4, y=2y - 4, -y = -4, then y=4. Now, to find x, let's substitute again. Go back to y=x. Substitue y for 4, leaving you with 4=x. So your solution is (4,4). Then check:
4=4 (correct)

and

4=2(4)-4
4=8-4
4=4 (correct).

There ya go.

[laughingman112]

What grade you in? Anyway, I just got a 98 in advanced pre-al, so maybe I can help. :P
We just did this shit last week. We'll use this.
y=x

y=2x-4

So take y=x for example, or x=y. Now, if x=y, let's substitute in for the x variable in the second equation. So y=2(y)-4, y=2y - 4, -y = -4, then y=4. Now, to find x, let's substitute again. Go back to y=x. Substitue y for 4, leaving you with 4=x. So your solution is (4,4). Then check:
4=4 (correct)

and

4=2(4)-4
4=8-4
4=4 (correct).

There ya go.

GOOD JOB man, give your self a high five for just telling him the answer and not letting him figure it out on his own. I lost all respect for your jakuza, I thought you were smarter than this. That equation was just child's play.

[Jakuza]

Well, im not exactly a fast learner, let alone an average learner.

[laughingman112]

Well, im not exactly a fast learner, let alone an average learner.

O well, you will learn. I was like that when I was young.

[Endless]

I see that KCBlack already explained it, but I'll try explaining it again in case you still don't understand.

Lets take the first problem. I suggest solving these by substitution because it's the easiest.

y=2x

y=3x-2

You see that Y is 2x, and it's also 3x-2. Therefore, 2x would equal 3x-2. If something equals something, and it equals something else; both those things will equal each other.

For example.
5=3+2
5=1+4
So, 3+2=1+4. Get it?

After you figure out what 'x' is, plug it into one of the equations to find out what 'y' is. Then you should always double check.

Whenever you see a y="equation", and another equation has a 'y' in it, you can substitute that 'y' for the equation. If you still need help, read the section in your book and do some extra problems.

[raikun09]

Im not really the one to ask, but this is pretty complicated to me.


You guys know about the 'system of equations' and the 3 ways to solving them, right?...

1.graphing
2.substitution
3.elimination


Well I need some help with substitution..


When its something like this...

y=2x

and

y=3x-2

or

y=x

y=2x-4

What exactly do you do?


Yeah, I took notes on it in school, but its still pretty fuzzy in my head.
Help is much apreciated. =/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

dont you just simplify by combining them.

so if it was
y=x and y=2x-4

then x+2x-4
|
3x-4

oh wait wait

your doing graphs and etc huh?
so there would be two equations....

you dont do nothing then man its just two seperate variables for two different equations

[Jakuza]

Well thanks, you guys. I think I got the pure concept now. Did 3 on my own just a minute ago. I solved and checked it, and they came out correct. =]

[raikun09]

thx to raikun09's 1337 skills in geometry............and those other guys>_>

[Jakuza]

thx to raikun09's 1337 skills in geometry............and those other guys>_>

This is algebra, my brother.

[laughingman112]

Well thanks, you guys. I think I got the pure concept now. Did 3 on my own just a minute ago. I solved and checked it, and they came out correct. =]

Jakuza, if you don't get subsitution you could use elimination. Which is like the same concept but I found it alot easier.

[Endless]

Jakuza, if you don't get subsitution you could use elimination. Which is like the same concept but I found it alot easier.

Correct me if I'm wrong, but elimination works best if the numbers are the same.

For example. If I got a problem like

y=2x+5
y=3x-5

Then I'd use elimination to do it because it's much easier. But life doesn't always give you problems that are that easy to do. I still suggest using substitution because you'll be using it a lot later on, plus it'll work with almost every problem.

It's been a long time since I've done anything like this so do correct me.

[Xynh]

Jakuza, if you don't get subsitution you could use elimination. Which is like the same concept but I found it alot easier.

It depends on the equation. Sometimes its faster an easier to use substitution than elimination, and vice-versa.