Quadratic Formula: 3x^2 - 7x - 19 = 0

[MastaLock]

3x^2 - 7x - 19 = 0
3x^2 - 7x = 19
x(3x - 7x) = 19
(1/2)(7) = 3 1/2

I am not sure where to go from here if I am doing this right????

 

[tkhunny]

Re: Quadratic Formula

3x^2-7x-19=0

I have no clue what you are doing.

Why not use the quadratic formula?

a = 3
b = -7
c = -19

 

[Goistein]

The quadratic formula is x=(-b+sqrt(b^2-4ac))/2a. Can anyone post this in code?

 

[jonboy]

The quadratic formula is x=(-b+sqrt(b^2-4ac))/2a. Can anyone post this in code?

Sure:

\(\displaystyle \L \;x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}\)


You can use TeXaide (download here, don't even type in an email address it will still work) which will convert the equation to LaTex codes.

 

[MastaLock]

Lost

x=-7+/- sqroot(-7)^2-4(3)(-19)/2(3)

x=-7+/- sqroot 49-4(3)(-19)/6

x=-7+/- sqroot 49+228/6

x=-7+/- sqroot 277/6

Can some one help me break this down any further? I can not seem to find the sqroot 277 yet? Or did I miss something here????? :wink:

 

[Denis]

Not bad, Masta; -(-7) = 7, not -7

> x=-7+/- sqroot 277/6

So that should be:
x = [7 +/- sqrt(277)] / 6 : cannot be simplified further

Start using BRACKETS, else you'll always be in trouble...
If you don't know why or when, ask your teacher :idea: