help with polynomials

[themaniac]

I barely understand it so can someone give me the answers and show me how to do them for this and please don't just say "do your own work"

 

1.  Write the product as a trinomial.

 

 (x + 2)(x + 4)

A.x2 + 8x + 8
B.x2 + 8x + 6
C.x2+ 6
D.x2 + 6x + 8

 

2.  Write the product as a trinomial.

 

 (m – 6)(m + 3)

A.m2 – 18
B.m2 – 3m – 18
C.m2 – 3m + 18
D.m2+ 3m – 18

 

3.  Write the product as a trinomial.

 

 (2x + 3)(4x – 2)

A.8x2+ 8x – 6
B.6x2 + 13x – 6
C.6x2 – 5x – 6
D.6x2 – 13x – 6

 

4.  Write the product as a trinomial.

 

 (3r – 4)(r + 8)

A.3r2 – 32
B.3r2 – 28r – 32
C.3r2+ 20r – 32
D.4r2 + 4r – 32

 

5.  Write the product as a trinomial.

 

 (k – 2)(k – 1)

A.k2– 2
B.k2 + 3k + 2 
C.k2 – 3k + 2
D.k2 – 3k – 2

[terrytek]

FOIL (First, Outside, Inner, Last). Remember that.

[themaniac]

OK but that doesn't really help me

[theelitegamer]

I'm not going to solve this but here's websites that'll help (they got me though alot of homework)

mathway.com

wolffarmahlpa.com 

 

also just google ''polynomials calculators''

[thatguyyouknow75]

the more you do them the easier theyll get, youll notice patterns and youll be able to do them VERY quickly in your head

[erty176]

FOIL is a good method, however I like to think of it as distributing twice. you take the first element and distribute it to the second polynomial. Then you take the second element and distribute it to the second polynomial.

For example:

(x+2)(x+4) 

 

(x)(x+4)  and 2(x+4)

 

Just be sure that you don't lose negatives

[Trik'Stari]

Polynomial calculator. Used it all the way through my last college algebra class.

http://www.webmath.com/polymult.html

 

May I never have to take math again.

 

I'm not going to solve this but here's websites that'll help (they got me though alot of homework)

mathway.com

wolffarmahlpa.com 

 

also just google ''polynomials calculators''

 

That's exactly what I did.

[terrytek]

So, first problem. (x + 2)(x + 4).

 

Applying the FOIL method.

 

1. F for First. You multiply the first variable in the sequence, x and x, so multiplying that gets you x²

 

2. O for Outer. You multiply the outer variables, in this case 4 and x, getting you 4x

 

3. I for Inner. You multiply the inner variables, 2 and x to get 4x

 

4. L for Last. You multiply the constants in the end, 2 and 4 to get 8.

 

Now add them all up. It's supposed to come out x²+4x+4x+8, or simplifying like terms x² +8x+8.

 

 

Repeat process with other problems.

[EpicGeekonFire]

If you just copy+paste answers you are setting yourself up for failure.

 

Here is a good website you can search with to learn different subjects. khanacedemy.org There are videos and practice questions to help you.

 

The basics of this is FOIL.

 

[themaniac]

If you just copy+paste answers you are setting yourself up for failure.

 

Here is a good website you can search with to learn different subjects. There are videos and practice questions to help you.

 

The basics of this is FOIL.

 

it was an online test all I had to do was select a box

[Stuff_]

it was an online test all I had to do was select a box

That's simply an excuse to cheat, and is setting you up for failure (not to mention simply cheating yourself).

 

Actually learning the material is 100 times better than cheating. 

 

YouTube some videos on the FOIL method. Maybe check out patrickJMT. He does a lot of math related videos, and shows you how to do it pretty easily.

[felixbearpig]

here is an example

(x+1)(x-3)

step 1. do FOIL

 

x*x    x*-3    1*x   1*-3

x^2   -3x      +x      -3

 

step 2. combine like terms

 

x^2  (-3x + x) -3

 

step 3 simplify 

 

so(x+1)(x-3)= x^2-2x-3

 

hope this example helps

[themaniac]

That's simply an excuse to cheat, and is setting you up for failure (not to mention simply cheating yourself).

 

Actually learning the material is 100 times better than cheating. 

 

YouTube some videos on the FOIL method. Maybe check out patrickJMT. He does a lot of math related videos, and shows you how to do it pretty easily.

I went through the lessons many times and just didn't understand it

[Stuff_]

Are you still having trouble with the foil method? No friends/relatives that know it could help you? 

[themaniac]

Are you still having trouble with the foil method? No friends/relatives that know it could help you?

i got it done thanks to the website trik'stari linked and nope non of my relatives know how to do it

[terrytek]

i got it done thanks to the website trik'stari linked

But you need to at least know how it's done in case you don't have a calculator like that.

[themaniac]

But you need to at least know how it's done in case you don't have a calculator like that.

it shows how to do the equation

[Nineshadow]

If for some reason you don't get this method : (x+2)(x+4) = x * (x+4) + 2 * (x+4) = bla bla bla , then let me explain it to you.

 

You have (x+2)(x+4).

We don't know what that does, but we do know that :

z*(x+y) = z*x + z*y. (whatever the x , y and z)

 

Back to our original equation (x+2)(x+4)

Let's have a = x + 2.

a(x+4) = a * x + a * 4 = (x + 2) * x + (x + 2) * 4 = x^2 + 2x + 4x + 8 = x^2 + 6x + 8.

 

Generally :

(a + b )*(c + d) = ac + ad + bc + bd (whatever the a , b , c and d)

 

That's if you really needed the explaination, even though it's simple enough without it.

[Nineshadow]

Polynomial calculator. Used it all the way through my last college algebra class.

http://www.webmath.com/polymult.html

 

May I never have to take math again.

 

 

That's exactly what I did.

Seriously?

That's what you do in college?

[Trik'Stari]

Seriously?

That's what you do in college?

For an algebra class? Yeah pretty much. It's online lol

 

Apparently people aren't aware of smartphones.

[Nineshadow]

For an algebra class? Yeah pretty much. It's online lol

 

Apparently people aren't aware of smartphones.

Well, your site can't do this :

(x^2 + 4 + x^3 - 9)(x^2 + 4 - x^3 + 9)

[ionbasa]

FOIL in my opinion is fairly retarded. Here is a visual look at what is happening:

 

 

 

 

This is known as the Area model/method (or less commonly known as the "box method"). Take each binomial and split it up on the sides of a box. Draw lattice in the box separating your terms. Then find the product in each square by multiplying the number at top and to the side of the box. Finally take the products inside the box and add them all together and simplify/combine like terms.

 

I teach this to students in college algebra (as I am a tutor), and this is by far the best way to show what is visually happening. There is also a neat video explaining this here:

 

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EDIT: I use this method when I have to manually multiply polynomials of order 4 or greater together. It helps you keep track of all the terms  .