Solve 2^2+5x+6 =-x^2-2x for x by factoring

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Twofacelol
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Solve 2^2+5x+6 =-x^2-2x for x by factoring

Postby Twofacelol » Tue Aug 11, 2009 11:42 pm

2^2+5x+6 =-x^2-2x

Do i add the x^2 and 2x to the other side? If so what would i do with the x^4? No idea how to do this :S

QM deFuturo
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Re: Solve for x by factoring

Postby QM deFuturo » Wed Aug 12, 2009 12:17 am

You want to combine like terms and get everything on one side of the equation, to end up with something in the form of

ax^2 + bx + c = 0


Then you can factor this equation using the various procedures for factoring a quadratic equation.

QM

Twofacelol
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Re: Solve for x by factoring

Postby Twofacelol » Wed Aug 12, 2009 12:55 am

Well you have to solve by, it says GCF/Double Bubble/Bottoms Up

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stapel_eliz
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Postby stapel_eliz » Wed Aug 12, 2009 11:18 am

Twofacelol wrote:Well you have to solve by, it says GCF/Double Bubble/Bottoms Up

I'm sorry, but this is something specific to your book. If you're not allowed to use standard methods, then you'll need to explain the method you are required to use. Thank you! :D

kklecan
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Re: Solve 2^2+5x+6 =-x^2-2x for x by factoring

Postby kklecan » Sat Aug 22, 2009 1:55 am

Do i add the x^2 and 2x to the other side? If so what would i do with the x^4?


Be careful here with like terms. If you're adding x^2 and x^2, you shouldn't be getting x^4. With that sorted out, you should be able to factor by one of the methods suggested in your book, though I agree with stapel_eliz--other than "GCF" I've never seen that terminology before.

JimCole
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Re: Solve 2^2+5x+6 =-x^2-2x for x by factoring

Postby JimCole » Mon Aug 24, 2009 8:33 pm

This is not a tough problem.

1. Start by adding x^2 to both sides and then add 2x to both sides. This gives you:

2^2 +5x+6+x^2+2x=0

It's the "=0" part that is important.

2. Now, do 2^2 and group your similar terms to get:

x^2 + 7x + 10 = 0

3. Since this thing equals 0, you can factor it without the quadratic equation (much easier that way):

(x + 5)(x + 2) = 0

4. This gives you both (x + 5) = 0 AND (x + 2) = 0

5. Solve each for x to get x = -5 and x = -2.

6. TADA!


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