Math Is Fun Forum

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Oops I posted th wrong problem!

This: 16x^2 +48xy + 36y^2 is the right one, sorry

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Wrong answer I was looking at your other problem!

Start by pulling a common factor out of 16,36 and 48. The highest common factor.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Alright, the common factor would be... 4, right?

I have to go now, after dinner and dishes ans such I think it'll take about a half an hour to 25 minutes.

Cya! Ill try to hurry

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Okay, I am going to take a little break now too.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Okay, cya then

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Wait, that was then.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Oooooh, alright then

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

So divide the whole trinomial by 4.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Alright

16x^2 +48xy + 36y^2

= 4x^2 + 12xy + 9y^2?

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

At this point please tell me what your teacher has taught you about the solutions of this ridiculous type of problem.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Well from what I can see...

Well look, remember the first problem I mentioned? This:  x² - 8x + 16? That was the example that I mistook for the problem. The answer given for that is (x - 4)²

Does that help?

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Not really, no wonder so many people hate mathematics.

We are looking for an answer that is in this form:

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Wait! I found another example.

It says:

a² + 2ab + b² = (a + b)²

Does that help, anymore?

It appears as though they want the exact opposite of what I've been doing...

Like instead of making (wx - y)²  into w²x² - 2wxy + y², they give me w²x² - 2wxy + y² and want my to make it back into (wx - y)²

I dunno... sorry for rambling haha

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Okay, they have essentially taught you nothing to prepare you to solve this so let us do it like this. We start with:

Notice that the right hand side is the same as your problem.

Do you follow the similarity between the two?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Uh... yeah

Do I need to try and simplify?

Last edited by misheeru (2011-01-19 16:23:57)

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Nope.

If somehow you could change that a^2 to a 4 and that b^2 into a 9 and that 2ab into a 12 you would have your problem. Yes?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Wait, what? Sorry, I'm a bit confused...

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

See the a^2 in the top expression, if it were a 4 it would look closer to your expression ( the bottom one ). Yes?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Yes... but...

(I'm really sorry by the way, my asked me to run to the store with her and I thought it would only take a few minutes but... I was wrong. Sorry!)

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Do not worry about it. If a^2 could become 4 then we would have the first part. Well if a^2 = 4 what is a?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Thanks

If a^2 = 4, then a = 2, right?

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

Yes, that is right so we have the first part. So we can substitute into the top equation.

clean up a little:

Remember we want this:

Look at the top expression again; see that b^2 if it were a 9 we would be even closer to the bottom expression.

Do you see that?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Should I do the same thing we did with a? So like, if b^2 = 9, then b =3?

---

Of Moons, Birds and Monsters

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Equations with parenthesis?

That is correct. So we can do more substituting.

Clean up a bit:

Looks like what you wanted to factor, does it not?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

misheeru

Member

Registered: 2010-02-18

Posts: 4,594

Re: Equations with parenthesis?

Mhmm. But what do we do about 12xy? It sorta seems like there is no room for it.

---

Of Moons, Birds and Monsters