solving Quadratics help

[jameshumphries47]

so i have this to work out 3X^2-34x+63 how would i work this out using fractioning?

help please!

[loccilucas]

so i have this to work out 3X^2-34x+63 how would i work this out using fractioning?

help please!

ew, thought I've never have to hear that word ever again after yr 11

[jameshumphries47]

ew, thought I've never have to hear that word ever again after yr 11

arghh im 2 years ahead of where i should, im only in year 9  

[_ASSASSIN_]

arghh im 2 years ahead of where i should, im only in year 9

use quadform on a ti-84. dun deal.

[Pugs501]

arghh im 2 years ahead of where i should, im only in year 9

Wait until proofs

[DeViLzzz]

Sorry OP I can't be of help.  I can tell you though that cheese is good and I love cheese.

[Toddwjp]

arghh im 2 years ahead of where i should, im only in year 9

 

i think you mean factorising, 

 

http://www.bbc.co.uk/schools/gcsebitesize/maths/algebra/quadequationshirev1.shtml

 

the bbc has some good guides and if your 2 years ahead dont worry too much, just make sure your school continues to provide maths work for you to do when you finish the required curriculum.

[LukaP]

x(1,2) = (-b +- sqrt(b^2 - 4ac)) / (2a)

 

where a,b,c are the numbers in your equation, so in your case, 

a=3

b=-34

c=63

 

so you get 2 solutions,

 

x1 = (34 + sqrt((-34)^2 - 4x3x63)) / 2x3 = 81

x2 = (34 - sqrt((-34)^2 - 4x3x63)) / 2x3 = 21

[Archangel1994]

x(1,2) = (-b +- sqrt(b^2 - 4ac)) / (2a)

 

where a,b,c are the numbers in your equation, so in your case, 

a=3

b=34

c=63

B=-34, not +34

[LukaP]

B=-34, not +34

whoops. didnt see the -. correcting

[Enderman]

x(1,2) = (-b +- sqrt(b^2 - 4ac)) / (2a)

 

where a,b,c are the numbers in your equation, so in your case, 

a=3

b=-34

c=63

 

so you get 2 solutions,

 

x1 = (34 + sqrt((-34)^2 - 4x3x63)) / 2x3 = 81

x2 = (34 - sqrt((-34)^2 - 4x3x63)) / 2x3 = 21

he said solving by factoring, not using the quadratic formula.

[jameshumphries47]

i dont get any of this im gonna speak to the teacher tommorow thanks for your help though guys 

[LukaP]

oh, one more thing. factorising is stupid, once you realise there is a formula, and how to get it, because then, it translates to all the other higher power polinomials

[LukaP]

he said solving by factoring, not using the quadratic formula.

check my other reply, quoted below

 

i dont get any of this im gonna speak to the teacher tommorow thanks for your help though guys 

there exists a formula (got through some higher level algebra) that can be adapted to a polinomial of any power, to get its results. i showed you the formula for a quadratic polinomial

 

as for factorising... below

 

oh, one more thing. factorising is stupid, once you realise there is a formula, and how to get it, because then, it translates to all the other higher power polinomials

[APrettyCoolWalrus]

use the quadratic formula?
https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1CHFX_enUS578US578&ion=1&espv=2&ie=UTF-8#q=quadratic%20formula

and use http://www.wolframalpha.com/ to help for future problems.

[Sammael]

(3x-7)(x-9)

 

 

PS, guys, he asked how to work it out using factoring, so there it is.

 

3x-7=0

x-9=0

 

x = 7/3, 9

[jameshumphries47]

oh, one more thing. factorising is stupid, once you realise there is a formula, and how to get it, because then, it translates to all the other higher power polinomials

yes factorising is really stupid! its just pathetic so many steps for nothing i will have a look at that later, i managed to get teh ansawer after 2 hours of trial and error

[thekeemo]

ew, thought I've never have to hear that word ever again after yr 11

where do you live where this is taken in year 11 I took this stuff in year 8

[loccilucas]

where do you live where this is taken in year 11 I took this stuff in year 8

Its in the GCSE, we started it in year 8 and kept doing it getting harder up till the exams(obviously alone side all the other subjects) . 

[APrettyCoolWalrus]

(3x-7)(x-9)

 

 

PS, guys, he asked how to work it out using factoring, so there it is.

 

3x-7=0

x-9=0

 

x = 7/3, 9

oh factoring! damn I remember that from 7th grade! ah the days...

[LukaP]

yes factorising is really stupid! its just pathetic so many steps for nothing i will have a look at that later, i managed to get teh ansawer after 2 hours of trial and error

ive always hated factorising, because it only really works with a quadratic, and only then, when the numbers work out for the Viet rule... (there is a way to make it work on a general polinomial, but the equations you get are far longer than just using the formula)

 

The sexy algorythm you use for higher degrees... -.-

http://mathworld.wolfram.com/PolynomialRoots.html

[jameshumphries47]

where do you live where this is taken in year 11 I took this stuff in year 8

i  dunno coz im not in year 11, east anglia  

[TideRower]

there exists a formula (got through some higher level algebra) that can be adapted to a polinomial of any power, to get its results. i showed you the formula for a quadratic polinomial

Do you mean that there is a  formula to solve polynomials of any degree?

That's not true. It can be proofen that polynoms with the degree of 5 and higher generally don't have a formula to find its roots.

[LukaP]

Do you mean that there is a  formula to solve polynomials of any degree?

That's not true. It can be proofen that polynoms with the degree of 5 and higher generally don't have a formula to find its roots.

well there isnt an exact one (as far as i know) but there are many that can get arbitrarily close to them (and me being a physicist, that means exactly there)

[Sammael]

I swear, looking at some of the other answers, I think they were trying to make it look so complicated you dropped out of school.

 

 

All you need to do is follow THIS and you will be OK kid !