Here's the quadratic I need to solve:
Now I know the solutions are but my book shows a number line that essentially has and Why is this the case? Why aren't they all "greater than" inequalities?
It is not failing, you are just not going to the end of things. I would draw a sign table :
And you get the correct answer and .
This is how I was taught to do it, makes it a lot easier to visualize
That table was a pain to build.
*PS* : you can achieve the same result using algebra but I forgot how