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anonymous
 one year ago
Help for a medal??
anonymous
 one year ago
Help for a medal??

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Identify the factors of x2  4x  21.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Hi. To get the factors of x^2  4x  21, let's put this equation into factored form.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0To start, please identify the a, b, and c components of this quadratic equation.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Alright, would the A be x^2, B=4x, C=21

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Very close, but more precisely, A and B will need to describe the coefficients of the x factors.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0B will be 4, A will be 1.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is this clear to you?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Great. Now, we know that the formula you wrote is a parabola since it's highest term is the x^2. This graph will take the shape of y=x^2 which is a parabola. Parabolas have how many xintercepts?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's exactly correct!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So when we go to factor your equation, we know that we're going to only have two pairs of x intercepts. Are you familiar with the factored form of a parabolic function?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's no problem at all.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Have you been taught about FOIL or expanding something that looks like: (x+1)(x1)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Great. So the idea is, the formula you gave me Ax^2 + Bx + C is called expanded form. That's because all the terms are out in the open. We need to get your Ax^2 + Bx + C into factored form. Factored form looks like: (x + j)(x + k)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So if I use FOIL on an example: (x + 3)(x + 4) I get: x^2 + 3x + 4x + 12 Which equals: x^2 + 7x + 12

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Do you see how that matches the shape of your formula?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We need to go from your formula into factored form.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We need to go into factored form because, for example: (x+1)(x+2) Your factors here are x+1 and x+2. And that is the answer to your problem :) So I need to show you how to get these factors.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Am I being clear? Please let me know if I'm being confusing

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0No I understand. It's just a little more difficult for me to follow since this is all in text, but I still understand.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Great. So let's look at your equation: x2  4x  21

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Let's learn what we know about FOILing and try to work backwards.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0dw:1433976603608:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0dw:1433976690825:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0And then do you subtract the 1x to the 3x?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I asked a question similar to this, and the helper said that you cross them both out, when I remember you having to add or subtract them

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So I cross them out then?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Sorry, I am unsure what the helper was doing for that particular problem. I have guesses, but I don't want to make something up and confuse anything :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0dw:1433976867455:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Let's start with trying to get the x^2 into our factored form. How can I make X^2 separating the X's?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We start off by setting up our two factors: (X)(X) Multiplying these two now would give us X^2.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah, I get that part but what I am confused by is what to do after. So you got x^2+3x+1x+3. But what do you do afterwards?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Sorry, I think I am being unclear. That is not the answer to your problem: x2  4x  21

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That was an example.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh. Sorry again. I see what you mean. Text is really hard today for some reason.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah, haha it's okay.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We're basically trying to take X^2 + 4X + 3 and shove it into (x + something)(x + something) form.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0To do that, we start off with our nice template. (x + a)(x + b) If we foiled this out now, our first term would be X^2, which satisfies the X^2 in our expanded equation.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0We still have to take care of the 4X and the +3.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Notice, when you do Inside and Outside of Foil, you get: a * X + b * X. Which can be written as (a + b)*X.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So our a plus our b has to equal the coefficient of X (the B value) in our expanded equation: x^2 + 4X + 3

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0And now we look at our last term which ends up being a*b. So our a*b must equal C in the expanded form.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So when choosing a and b values for your factored form: (X + a)(X + b) You must satisfy two constraints: 1) a * b must be C. 2) a + b must be B.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Does this make any sense?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah. I can actually handle the problem from here. Thank you for your time! Since you spent a good amount of time with me, I'll give you a medal and fan!
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