# I have holes in my math, help me.

What is happening here?
x2 – x – 2 = 0
(x – 2)(x + 1) = 0
x = 2 or x = –1

This is related to domain and ranges, finding the possibilities of the domain.

I would like to just see the process of how to solve this and then knowing what this actually is in mathematical terms (I'm assuming it is basic algebra, but what within algebra is this considered?)

Sorry for my blatant ignorance, I am getting back into math right now.

Related Precalculus Mathematics Homework Help News on Phys.org
mfb
Mentor
x2 means x2?
Going from the first to the second line is a bit tricky (basically clever guessing), but can you derive the first line from the second?

To come from the second to the third: how can a product of two factors be zero? There are two options, and those give you the solutions.

Mark44
Mentor
What is happening here?
x2 – x – 2 = 0
I'm guessing you mean x2 - x - 2 = 0. I used HTML tags to make the superscript exponent. A simpler way is to write an exponent using the ^ character, like this:
x^2 -x - 2 = 0
(x – 2)(x + 1) = 0
x = 2 or x = –1

This is related to domain and ranges, finding the possibilities of the domain.

I would like to just see the process of how to solve this and then knowing what this actually is in mathematical terms (I'm assuming it is basic algebra, but what within algebra is this considered?)
The equation you wrote is a quadratic equation, so called because the highest degree term (x2) is a squared term (quadratus is Latin for square).

What was done in the work you show is called factoring, with the idea that if you know that two things multiply to make zero, then one or the other of them must be zero.
Sorry for my blatant ignorance, I am getting back into math right now.

verty
Homework Helper
If you need book recommendations, ask in the book section and you'll certainly get help.

The process used in this question is called factoring a quadratic equation, it is a shorter method than the longer "completing the square", although there is also the quadratic formula that one can use.

HallsofIvy