The Homework Help Thread

[Doctor XFizzle 8,651]

My head hurts from just reading this. I haven't done any meaningful math problems since 2007. I can help with comedic relief while you do your math homework?

[Why-Gnome-Ear-Fifty 400]

My thread got buried

 

But yeah, there's plenty of people willing to help for sure. Probably too many.

[Talemage 47]

MOAR. (entity in which you worship),I'm so stupid.

 

Determine whether each system of equations is consistent, inconsistent or dependent.

1. x-2y=5

5x-10y=25

I'm supposed to do something, and I end up with(for the first equation), y=(1/2x)-(5/2) Or something.

 

2. 6x+5y=1

6x+5y=8

 

Pi. 16x+8y=4

4x-2y=1

 

4. 3x-y=5

3x+y=-2

 

5. 5x+4y+2=0

6x-3y+5=0

 

 

By the way, I'm not trying to put a burden on any of you. You're welcome to solve at least one of it, and give an explanation so I can do it myself, so I won't remain an idiot.

 

Draw the graphs of the two equations of each system in the same coordinate plane and find the solution set of the problem.

 

1. 2x+y=4

x-y=-1

 

2. x+2y=4

x+2y=-6

 

3. x+y=4

x-y+-2

 

4. x-2y=6

x+y=4

 

5. x-y=7

3x-y=-3

 

 

That's all for this week.

[Marshmallow 1,134]

MOAR. (entity in which you worship),I'm so stupid.

 

Determine whether each system of equations is consistent, inconsistent or dependent.

1. x-2y=5

5x-10y=25

I'm supposed to do something, and I end up with(for the first equation), y=(1/2x)-(5/2) Or something.

 

2. 6x+5y=1

6x+5y=8

 

Pi. 16x+8y=4

4x-2y=1

 

4. 3x-y=5

3x+y=-2

 

5. 5x+4y+2=0

6x-3y+5=0

 

 

By the way, I'm not trying to put a burden on any of you. You're welcome to solve at least one of it, and give an explanation so I can do it myself, so I won't remain an idiot.

 

Draw the graphs of the two equations of each system in the same coordinate plane and find the solution set of the problem.

 

1. 2x+y=4

x-y=-1

 

2. x+2y=4

x+2y=-6

 

3. x+y=4

x-y+-2

 

4. x-2y=6

x+y=4

 

5. x-y=7

3x-y=-3

 

 

That's all for this week.

 

Yay! Math thread!

Let's get down to it.

 

 

1. x-2y=5

5x-10y=25

 

x=2y+5

 

5(2y+5) - 10y=25

10y +25 - 10y =25

25 = 25

 

So I guess this one is consistent. What I did is that in the first place I just isolated x (could've been y too, it doesn't really matter) Then I substituted it in the other equation and solved. It's the same thing for the other problems.

 

If you get the same number after simplifying, then it's consistent. If you don't then it's non-consistent and if there's a variable it's dependent.

 

2. 6x+5y = 1

6x+5y=8

 

6x=8-5y

x= (8-5y)/6

 

6((8-5)/6) + 5y = 8

8 - 5y + 5y = 8

8 = 8, so that one would be consistent as well

 

3. 16x + 8y = 4

4x-2y=1

 

4x = 1+2y

x= (1+2y)/4

 

16((1+2y)/4) + 8y = 4

4(1+2y) + 8y = 4

4+8y + 8y = 4

4 + 16y = , there's still a variable in there so it's dependent.

 

 

4. 3x - y = 5

3x + y = -2

 

-y = 5 -3x

y= -5 + 3x

 

3x + (-5+3x) = -2

3x - 5 + 3x = -2

-5 = -2, so that's non-consistent

 

Hope this helped, I'll let you do the 5th one by yourself

Edited July 17, 2012 by Marshmallow

[Bronium 512]

Hey guys I need help with this. This is a bit beyond me (and all my teachers apparently)

 

f(x) = Cos (x) (This is for simplicity. I wonder what it will look like with coefficients. Bonus points if you do f(x) = a Cos(bx)

 

Here's what I got so far.

 

f'(x) = Lim Cos (x+h) - f(x)

as h approaches 0 h

 

There is an answer ( It's -pi Sin (x) )

( 180 )

 

Can someone show the method for solving that? I showing it to (my favorite and smartest (I think)) maths teacher and she said she'll get back to me.

 

Good luck!

[Champion RD92 8,654]

someone please help me, i need to solve this equation and i can't get the right answer for some reason

 

2^2x - 8 x 2^x + 16 = 0

[Silverhoof 2,839]

The meaning of life is: 42

 

thats all you need to know

2^2x - 8 x 2^x + 16 = 0

 Besides its already solved. Look the answer is, = 0

all that worry over nuthin.

 

now go enjoy some pizza and beer.

[Champion RD92 8,654]

The meaning of life is: 42

 

thats all you need to know

 

 Besides its already solved. Look the answer is, = 0

all that worry over nuthin.

 

now go enjoy some pizza and beer.

 

The answer isn't 0, I'm supposed to find out what x is... -___-

[Silverhoof 2,839]

There is only one hope for you then. Get a great excuse more believable than, "the dog ate my homework."

 

You should apologize and tell your professor, "I'm sorry I could do my homework because of...ZOMBIES!" scream, run from the room and drop the class.

It'll sound a lot better than, "I posted my homework on an internet forum about ponies and no one would do my work for me,"

[Champion RD92 8,654]

There is only one hope for you then. Get a great excuse more believable than, "the dog ate my homework."

 

You should apologize and tell your professor, "I'm sorry I could do my homework because of...ZOMBIES!" scream, run from the room and drop the class.

It'll sound a lot better than, "I posted my homework on an internet forum about ponies and no one would do my work for me,"

 

Well it's only one problem, it's not like I'm gonna fail the assignment lol

[Silverhoof 2,839]

Well it's only one problem, it's not like I'm gonna fail the assignment lol

Darn. I was gonna run that joke into the ground.

 

So whats this equation for?The only really hard one I ever paid attention to was the one that figured out how many intelligent races there were in the galaxy. that was wizard cool.

[Betez 1,734]

Sorry, I'm only in Algebra 1. It looks like a Quadratic Trinomial. Have you tried the Quadratic Forumla?

[Champion RD92 8,654]

Darn. I was gonna run that joke into the ground.

 

So whats this equation for?The only really hard one I ever paid attention to was the one that figured out how many intelligent races there were in the galaxy. that was wizard cool.

 

It's for...my homework?...

 

It's just an exponential equation, it's nothing special.

 

Sorry, I'm only in Algebra 1. It looks like a Quadratic Trinomial. Have you tried the Quadratic Forumla?

 

The Quadratic Formula ain't gonna work, it's an exponential function, not a quadratic function.

[Silverhoof 2,839]

 

It's just an exponential equation, it's nothing special.

The Quadratic Formula ain't gonna work, it's an exponential function, not a quadratic function.

Oh great. now my head hurts.

ummmm. I can do my tax forms...

[Betez 1,734]

It's for...my homework?...

 

It's just an exponential equation, it's nothing special.

 

 

The Quadratic Formula ain't gonna work, it's an exponential function, not a quadratic function.

Shit, I don't know then

[MelancholicMemory 2,022]

I'm going to try to solve it. Let's hope I remember math from high school

I think it has something to do with logarithms, but I'm not sure. I tried a lot of techniques, but all I could really accomplish is simplifying it to

 

2^2x - 16^x +16 = 0

 

Sorry.

Edited February 27, 2013 by MelancholicMemory

[Harmonic Revelations 8,833]

It's -4, I think.

[Standard User 2,127]

If nothing else works, stick it in a graphing calculator and check where the line/parabola/whatever crosses the x-axis.

 

I'm in Pre-Calculus, so all I work with now is letters and words... 

[Yes-Man 597]

My incredibly stupid brain hurts after this.

 

I need more help with that.

Edited February 27, 2013 by ~Lonesome Dovahkiin~

[Totally Ducklett 181]

Google, anyone?

Edited February 27, 2013 by Ducksquack

[Wubsie 1,123]

Damn I thought I had it...:/

Sorry but I can't get this for you bro...

[Pinkazoid 3,493]

I solved it, for some reason, I consider solving them in my head is fun xD

 

Anyways, you can just use a graphing calculator :v

[Evilshy 5,089]

I'm going to try to solve it. Let's hope I remember math from high school

 

I think it has something to do with logarithms, but I'm not sure. I tried a lot of techniques, but all I could really accomplish is simplifying it to

 

2^2x - 16^x +16 = 0

 

Sorry.

 

Hate to tell you, but that's not even right

8 and 2^x can't be multiplied because they don't have the same base.

 

 

Anyway, I forget how to do this sort of thing, so meh :/

Edited February 27, 2013 by Evilshy

[Moon Rat 4,772]

X=2

 

Now let's Try plugging that in shall we?

 

 

2^{2 x 2} - 8 x 2²+ 16 = 0

Okay first off, the exponent

2x2=4

2⁴=16

Then 2²=4

 

Now we have -16 - 8 x 4 + 16

Multiplying we get 16 -32 + 16

16-32=-16+16=0

 

There you go

 

I THINK I got this right

Edited February 27, 2013 by ~Lovable Luna~

[Nohbdy 4,108]

X=2

 

Now let's Try plugging that in shall we?

 

Okay first off, the exponent

2x2=4

2⁴=16

Then 2²=4

 

Now we have -16 - 8 x 4 + 16

Multiplying we get 16 -32 + 16

16-32=-16+16=0

 

There you go

 

I THINK I got this right

You are absolutely right.

 

I did it this way:

 

2^(2x)-8*2^x+16

 

Substitute a for 2^x.

 

a^2 -8a+16

 

= (a-4)^2

 

a = 4

 

Substitute 2^x for a.

 

2^x = 2^2

 

Ignore the like bases.

 

x = 2