But not easy for me, i can't find out what's the value in ''X'' when the function is :

0=12X(X)-160x+400

edit: 0=12x^2-160x+400

The 12x(x) is 12x2

I can't put the little 2 in top.. please help me guys i have an exam this week and all my numbers I do in my book are wrong...

This post was edited by MarcMorrison on Oct 5 2013 03:38pm

Use the quadratic formula.

http://www.purplemath.com/modules/quadform.htm

This post was edited by carteblanche on Oct 5 2013 03:38pm

OMG THANK U LOL NEVER THOUGHT OF TJAT

i have the quadratic formula in my calculator, i tried doing the fckin number for 30 minutes and nothing worked untill you helped me out. If i had FG i'd definatly give it to you because im so happy i did it

This post was edited by MarcMorrison on Oct 5 2013 03:40pm

lol chill brother, its just a quadratic formula

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memorize the quadratic formula for sure
Although some of the problems you get you'll be able to solve without it, you can use it for any problem

any problem involving finding the zeroes of a quadratic function maybe

try deriving it a few times and it might stick in your head better

If you're having trouble with the quadratic formula, you can always do it the long way.

Those numbers are inconveniently big, so divide by 2. Note that you're dividing BOTH sides by two, but 0/2 == 0, so that side doesn't change. This should always be your first step if you notice that the 'a', 'b', and 'c' from the quadratic formula all have a common divisor.

6x^2 - 80x + 200 = 0

so either your options are

(6x _____) (x_______)

or

(3x_____) (2x _______)

where the blanks are +/- some numbers that multiple together to get 200. Since the 200 is positive and the 80 is negative, know it's going to be (minus) in both sides. (it has to be either both minus or both plus in order to get the +200). So now you just need to work out the various factors of 200.

1 * 200
2 * 100
4 * 50
5 * 40
8 * 25
10 * 20

Then you go through these possible combinations until you find something that FOILs out to give you -80x. You end up choosing
( 3x - 10 ) ( 2x - 20 ) = 0

which tells you that there are two possible ways for the left hand side to equal zero.

Case 1: 3x - 10 == 0, so x == 10/3
Case 2: 2x - 20 == 0, so x == 10

this

a=12
b= -160
c=400

160[+-] Sqrt (25,600- 4(12)(400))/ [2*12]

160[+-] Sqrt (6400)/ (24)

Answer is 10 or 3.33 bar