math

Hello! Seems like a school homework, but i can help you. First of all you have to read this: http://en.wikipedia.org/wiki/Quadratic_equation .
Just, "play" with your first equation and the solution in this Quadratic equation is simple:

1) Image 1=>

http://latex.codecogs.com/gif.latex?2x^2+9x%3D-5\Rightarrow%202x^2+9x+5%3D0%20\Rightarrow%20%28divide.by.2%29\Rightarrow%20x^2+\frac{9}{2}x-\frac{5}{2}%3D0
2) Fianlly(remember the Quadratic equation):
Image 2=>

http://latex.codecogs.com/gif.latex?x%3D\frac{-\frac{9}{2}\pm%20\sqrt{%28\frac{9}{2}%29^2-4%28-\frac{5}{2}%29}}{2}\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\sqrt{\frac{81}{4}-10}}{2}%20\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\sqrt{\frac{41}{4}}}{2}%20\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\frac{\sqrt{41}}{2}}{2}%20\Rightarrow%20{\color{DarkRed}\mathbf{x%3D\frac{-9\pm%20\sqrt{41}}{4}}}

Have a nice day!

Hello! Seems like a school homework, but i can help you. First of all you have to read this: http://en.wikipedia.org/wiki/Quadratic_equation .
Just, "play" with your first equation and the solution in this Quadratic equation is simple:

1) Image 1=>

http://latex.codecogs.com/gif.latex?2x^2+9x%3D-5\Rightarrow%202x^2+9x+5%3D0%20\Rightarrow%20%28divide.by.2%29\Rightarrow%20x^2+\frac{9}{2}x+\frac{5}{2}%3D0
2) Fianlly(remember the Quadratic equation):
Image 2=>

http://latex.codecogs.com/gif.latex?x%3D\frac{-\frac{9}{2}\pm%20\sqrt{%28\frac{9}{2}%29^2-4\frac{5}{2}}}{2}\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\sqrt{\frac{81}{4}-10}}{2}%20\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\sqrt{\frac{41}{4}}}{2}%20\Rightarrow%20x%3D\frac{-\frac{9}{2}\pm%20\frac{\sqrt{41}}{2}}{2}%20\Rightarrow%20{\color{DarkRed}\mathbf{x%3D\frac{-9\pm%20\sqrt{41}}{4}}}

Have a nice day!

Just ignore my first post . I did 1 mistake with a "-".
By the way, to moderators: if possible delete my first post and [this] post. Thank you!

Hi Dms,
Can you show us how to put the LaTex in like that?
Reinout-g and i are very impressed.
We want a lesson please.
Melody

jilliennek:

solve equation for x :
2x^2 + 9x = -5

We have all been pretty wowed by Dms's solution.
We have never seen LaTex in here like this before and we would love to know how it is done.
Please show us Dms.

However, I think Dms may have made the problem more difficult than it really is ('a' does not need to be 1)
quadratic formula.JPG

2x ² + 9x + 5 = 0

a=2, b=9 c=5

x=[ -9 ± sqrt( 81-40) ] / 4

x=[ -9 ± sqrt( 41) ] / 4