In Need Of Math Help!

[Sp4de]

Sp4de I'm 99% possitive that 2nd one is completely incorrect.

 

 

 

Yeah I figured, maybe I should make sure I can do this stuff before I try to explain. :shame:

[Foooman]

this is regarding what he said ingame.

 

 

 

9x(sq) + 24x +16

 

 

 

(ax+B)(cx+d) is the answer.

 

 

 

in this:

 

 

 

a * c = 9

 

b * d = 16

 

(a * d) + (c * B) = 24

 

 

 

This means:

 

 

 

a and c must multiply to equal 9.

 

These choices are...

 

3,3

 

9,1

 

 

 

So:

 

 

 

The answer is

 

 

 

(3x_B)(3x_d)

 

-or-

 

(9x_B)(x_d)

 

 

 

Now we know that b and d must multiply to equal 16.

 

 

 

So b and d can be:

 

4,4

 

16,1

 

2,8

 

 

 

Now we have all choices of:

 

 

 

(3x+4)(3x+4)

 

(3x+16)(3x+1)

 

(3x+2)(3x+8)

 

(9x+4)(x+4)

 

(9x+16)(x+1)

 

(9x+2)(x+8)

 

(9x+1)(x+16)

 

(9x+8)(x+2)

 

 

 

From this we can conclude:

 

 

 

(3x+4)(3x+4) = 9x(sq) + 24x + 16

 

 

 

 

 

QED

[lifeguard200]

this is regarding what he said ingame.

 

 

 

9x(sq) + 24x +16

 

 

 

(ax+B)(cx+d) is the answer.

 

 

 

in this:

 

 

 

a * c = 9

 

b * d = 16

 

(a * d) + (c * B) = 24

 

 

 

This means:

 

 

 

a and c must multiply to equal 9.

 

These choices are...

 

3,3

 

9,1

 

 

 

So:

 

 

 

The answer is

 

 

 

(3x_B)(3x_d)

 

-or-

 

(9x_B)(x_d)

 

 

 

Now we know that b and d must multiply to equal 16.

 

 

 

So b and d can be:

 

4,4

 

16,1

 

2,8

 

 

 

Now we have all choices of:

 

 

 

(3x+4)(3x+4)

 

(3x+16)(3x+1)

 

(3x+2)(3x+8)

 

(9x+4)(x+4)

 

(9x+16)(x+1)

 

(9x+2)(x+8)

 

(9x+1)(x+16)

 

(9x+8)(x+2)

 

 

 

From this we can conclude:

 

 

 

(3x+4)(3x+4) = 9x(sq) + 24x + 16

 

 

 

 

 

QED

 

 

 

ok from the problem b4, ths is waht i though you had to do.

 

 

 

this is what i thought you had to do.

 

 

 

Example

 

 

 

9x(sq) + 24x + 16

 

 

 

step 1. Find the two numbers that you can multiply to get 16 (4,4) (2,8) (16,1) to name a few

 

 

 

step 2. Do 9 times 4, plus 4. Or 9 times 2 plus 8, and reversed and etc. ( do you get what im saying) Until you got to 24. so this isnt right?

[mad4u689]

this is regarding what he said ingame.

 

 

 

9x(sq) + 24x +16

 

 

 

(ax+B)(cx+d) is the answer.

 

 

 

in this:

 

 

 

a * c = 9

 

b * d = 16

 

(a * d) + (c * B) = 24

 

 

 

This means:

 

 

 

a and c must multiply to equal 9.

 

These choices are...

 

3,3

 

9,1

 

 

 

So:

 

 

 

The answer is

 

 

 

(3x_B)(3x_d)

 

-or-

 

(9x_B)(x_d)

 

 

 

Now we know that b and d must multiply to equal 16.

 

 

 

So b and d can be:

 

4,4

 

16,1

 

2,8

 

 

 

Now we have all choices of:

 

 

 

(3x+4)(3x+4)

 

(3x+16)(3x+1)

 

(3x+2)(3x+8)

 

(9x+4)(x+4)

 

(9x+16)(x+1)

 

(9x+2)(x+8)

 

(9x+1)(x+16)

 

(9x+8)(x+2)

 

 

 

From this we can conclude:

 

 

 

(3x+4)(3x+4) = 9x(sq) + 24x + 16

 

 

 

 

 

QED

 

 

 

ok from the problem b4, ths is waht i though you had to do.

 

 

 

this is what i thought you had to do.

 

 

 

Example

 

 

 

9x(sq) + 24x + 16

 

 

 

step 1. Find the two numbers that you can multiply to get 16 (4,4) (2,8) (16,1) to name a few

 

 

 

step 2. Do 9 times 4, plus 4. Or 9 times 2 plus 8, and reversed and etc. ( do you get what im saying) Until you got to 24. so this isnt right?

 

 

 

That's almost right, which doesn't work in mathematics :(

 

 

 

When there's no coefficient in front of the x^2 term - such as in x^2 + 4x + 4 - that works fine. But when there IS a coefficient in front of the x^2 term, such as in 2x^2 + x - 6, you need to take that into account. So what factors could lead to you getting a 2x^2 term?! The only way to get x^2 is by multiplying an x term and an x term! So you know that it will need to start out with (2x + __ ) (x + __), because then when you multiply out this 2x and x, you will get 2x^2.

[Foooman]

(3x+4)(3x+4)----------{(3*4)+(3*4)}--------24

 

(3x+16)(3x+1) ---------{(3*1)+(3*16)}--------51

 

(3x+2)(3x+8) -------{(3*8)+(3*2)}------30

 

(9x+4)(x+4) ---------{(9*4)+(1*4)} ------40

 

(9x+16)(x+1) ------ {(9*1)+(1*16)} ------25

 

(9x+2)(x+8) -------- {(9*8)+(1*2)} --------74

 

(9x+1)(x+16) ------- {(9*16)+(1*1)} -----145

 

(9x+8)(x+2) ------- {(9*2)+(1*8)} --------26

 

 

 

These are all posible solutions. and yes you do the same thing to conclude the final answer after this step...

 

 

 

Since (3x+4)(3x+4) has a middle term of 24..it is the correct one.

[lifeguard200]

(3x+4)(3x+4)----------{(3*4)+(3*4)}--------24

 

(3x+16)(3x+1) ---------{(3*1)+(3*16)}--------51

 

(3x+2)(3x+8) -------{(3*8)+(3*2)}------30

 

(9x+4)(x+4) ---------{(9*4)+(1*4)} ------40

 

(9x+16)(x+1) ------ {(9*1)+(1*16)} ------25

 

(9x+2)(x+8) -------- {(9*8)+(1*2)} --------74

 

(9x+1)(x+16) ------- {(9*16)+(1*1)} -----145

 

(9x+8)(x+2) ------- {(9*2)+(1*8)} --------26

 

 

 

These are all posible solutions. and yes you do the same thing to conclude the final answer after this step...

 

 

 

Since (3x+4)(3x+4) has a middle term of 24..it is the correct one.

 

 

 

just one question more, where did the (3X+16)(3X+1) and so on, come from, i know where the 9X came from but where the 3x?

 

 

 

EDIT. NVM I FOUND OUT WHERE THE 3 CAME FROM

 

 

 

Going To Sleep Now, thanks everyone and keep posting cause this stuff aint getting easier lol :shame: :lol:

[Foooman]

In all of this I would take from it:

 

 

 

 

 

In.

Ax(sq) + Bx + C 



(ax+B)(cx+d) is the answer. 



in this: 



a * c = A

b * d = C

(a * d) + (c * B) = B

 

 

 

EDIT: going to sleep.

[Bloodyrb]

Here is an example of a problem

 

 

 

Factor the Trinomial

 

 

 

X[squared] + 6X+9.

 

 

 

(X + 3)squared

 

 

 

Clue - quote me and you'll see the tiny text...

 

 

 

EDIT: Here we go...

 

 

 

 

 

 

huh

 

 

 

(2x X 6) (2x X 6) =

 

 

 

4xÃÆââ¬Å¡Ãâò + 12x + 12x + 36 =

 

----------------------------

 

4xÃÆââ¬Å¡Ãâò + 24x + 36

 

 

 

 

 

right?

[greenslime89]

Here is an example of a problem

 

 

 

Factor the Trinomial

 

 

 

X[squared] + 6X+9.

 

 

 

(X + 3)squared

 

 

 

Clue - quote me and you'll see the tiny text...

 

 

 

EDIT: Here we go...

 

 

 

 

 

 

huh

 

 

 

(2x X 6) (2x X 6) =

 

 

 

4xÃÆââ¬Å¡Ãâò + 12x + 12x + 36 =

 

----------------------------

 

4xÃÆââ¬Å¡Ãâò + 24x + 36

 

 

 

 

 

right?

 

Yes but in an exam you would lose a mark for that, you should take out a common factor, in this case 4, this would give you 4(X^2 + 6X + 9)

[lifeguard200]

ok thanks guy im back and i get most of this stuff now, but i still got some i need help with. ill try to finish what i can get to and then ill ask a few more questions

[greenslime89]

Pythagorus theorum rocks - I was raking through some old school papers and I found this test paper I did in first year (aged 12 Scotland system is different to most others)

 

 

 

 

yes my writing was messy - SUE ME :twisted:

[SanFranciscoGiants]

:shock: :roll: Wow ive never heard of trinomials and I cant understand anything ur writing :lol:

[mad4u689]

Pythagorus theorum rocks - I was raking through some old school papers and I found this test paper I did in first year (aged 12 Scotland system is different to most others)

 

 

 

 

yes my writing was messy - SUE ME :twisted:

 

 

 

Hehhee, I saw a t-shirt like that on cafepress :D

[LP]

:( :cry:

[Quasar889]

You guys think these trinomials are nasty, wait till you get to AP stat :shock:

 

They have me doing quartic regressions and 2 Sample T-Tests! ZOMG! I <3 math though, so it isn't as bad as it sounds. (Specially with a TI-84 :3> ) I love that calc.

[Foooman]

You guys think these trinomials are nasty, wait till you get to AP stat :shock:

 

They have me doing quartic regressions and 2 Sample T-Tests! ZOMG! I <3 math though, so it isn't as bad as it sounds. (Specially with a TI-84 :3> ) I love that calc.

 

 

 

Just got my AP Stat test score from last year. 5 :mrgreen:

 

Stat is easy; it's English, with some harmless math.

[weezcake]

You guys think these trinomials are nasty, wait till you get to AP stat :shock:

 

They have me doing quartic regressions and 2 Sample T-Tests! ZOMG! I <3 math though, so it isn't as bad as it sounds. (Specially with a TI-84 :3> ) I love that calc.

 

 

 

Eh, personally, I believe that stat is equivalent to basic algebra. I don't understand why people think it's so hard! (I did have trouble in calculus though, hehe)

 

 

 

Stats = get formula/procedure, plug in number, get answer. :mrgreen:

[lifeguard200]

ok now theres a differnt problem, it says 9X[squared]81. Is this one difficult?

[Foooman]

(3x+9)(3x-9)

[lifeguard200]

x^3+11x^2+28x

[Foooman]

x(cubed)+11x(sq)-28x

 

 

 

note that the last term has an x. This means that one of the factors is going to have 2 x's.

 

note that that the first term is cubed. This means that one of the factors is gonig to have an x(sq).

 

note that the both signs are positive. This manes that both factors will have positive signs.

 

 

 

Now we need the factors of 28 that add up to 11. These happen to be 7 and 4.

 

 

 

(x(sq)+4x)(x+7)

 

(x(sq)+7x)(x+4)

 

Are both correct answers.

[quakingmoose]

EDIT - There is the basics on Factoring, if you wanna know how to reverse.. you simply multiply the ( )'s together, then you group all like terms and booya! theres Standard form.

 

 

 

With Trinomials, theres:

 

 

 

Standard form - y=ax(squared) + bx + c

 

 

 

X-Intercept form - y=(x+a)(x+B) , a & b = any number

 

 

 

You can switch back and forth between through several methods.

 

 

 

If you would like to go from Standard to X-Intercept (this is hard, Ill try to explain) you need to do this:

 

 

 

Example 1) a = 1 , b = 1 , c = -6

 

 

 

So the equation is - y=x(squared) + x - 6 >>>Are you with me?

 

 

 

To get the leading term of x(squared), each first term is x, therefore:

 

 

 

y = (x )(x )

 

 

 

Then we need to find what else are in the ( ). The product of the last terms must be -6. Possible answers are:

 

 

 

+ 6 and - 1

 

- 6 and +1

 

+ 3 and - 2

 

- 3 and +2

 

 

 

This tells us that our possible answers to this problem will be:

 

 

 

(x+6)(x-1)

 

(x-6)(x+1)

 

(x+3)(x-2)

 

(x-3)(x+2)

 

 

 

Then you need to test, to see which one is the RIGHT answear, each of these pairs to see which will yield the correct middle term when they are added together.

 

 

 

(x + 6)(x - 1) gives middle term 5x.

 

(x - 6)(x + 1) gives middle term -5x.

 

(x + 3)(x - 2) gives middle term +x. YEA!!!!!

 

(x - 3)(x + 2) gives middle term -x.

 

 

 

Therefore the answear is y = (x + 3)(x - 2), in X-intercept form.

 

 

 

THIS WHOLE PROCESS IS CALLED FACTORING!

 

 

 

My brain hurts now.

[nightshade53]

I swear they (expressions of order 2) are called Binomials..as in the binomial expansion :roll: , then cubics (order 3) and quartics (order 4)..

 

 

 

to solve to general binomial you do this:

 

 

 

A(x^2)+B(x)+C = 0 <-- Set it equal to 0

 

 

 

then use the formula:

 

 

 

x = (-(B^2) ÃÆââ¬Å¡Ãâñ ÃÆâÃâ¹Ã¢â¬Â Ãâ¦Ã¡((B^2)-(4*A*C)))/2*A

 

 

 

:XD:

[Aznhuskarl]

x = (-(B^2) ÃÆââ¬Å¡Ãâñ ÃÆâÃâ¹Ã¢â¬Â Ãâ¦Ã¡((B^2)-(4*A*C)))/2*A

 

 

 

ah...that formula...a lot fo ppl from my high school SINGS that formula with that Carmen Campagne's song.

 

I used to be able to do all those binomals and trinomals without writting any calculation. Ahh...high school math. That was pretty easy.

[lifeguard200]

y=2x+7 over 14

 

 

 

i put it like problem wise and it looks wierd so i had to type it this way