# Thread: Trying to revise for Algebra - Help needed!

1. ## Trying to revise for Algebra - Help needed!

Hi everyone, I am at University and having to do Algebra as part of one of my modules. I have a test coming up in the next few weeks and I am trying to revise for it.

I need to know how to solve quadratic equations. The example I have is... x² + 3x - 6 = 0

I have tried looking through my notes and books but can't seem to get my head around it! Can anyone break it down for me to help me understand?

2. Originally Posted by Laurenbean
Hi everyone, I am at University and having to do Algebra as part of one of my modules. I have a test coming up in the next few weeks and I am trying to revise for it.

I need to know how to solve quadratic equations. The example I have is... x² + 3x - 6 = 0

I have tried looking through my notes and books but can't seem to get my head around it! Can anyone break it down for me to help me understand?

You can solve a quadratic equation by a number of methods such as, factoring, completing the square, using the quadratic formula etc. If we solve it by completing the square;

$x^2+3x-6=0$

$\left(x+\dfrac{3}{2}\right)^2-\dfrac{9}{4}-6=0$

$\left(x+\dfrac{3}{2}\right)^2=\dfrac{33}{4}$

$x=\dfrac{-3\pm{\sqrt{33}}}{2}$

3. Originally Posted by Laurenbean
Hi everyone, I am at University and having to do Algebra as part of one of my modules. I have a test coming up in the next few weeks and I am trying to revise for it.

I need to know how to solve quadratic equations. The example I have is... x² + 3x - 6 = 0

I have tried looking through my notes and books but can't seem to get my head around it! Can anyone break it down for me to help me understand?