Question

Simplify.. again!

Answer 1

what to simplify?

Answer 2

\[\frac {x^{2}-12x+20}{x-10}\]

Answer 3

you have to factor the top.

Answer 4

So, it'd be, x - 3x + 5?

Answer 5

list the factors of the 3rd number 20
1,20
2,10
4,5

do any add up to 12
if so, that is the pair to use.
the sign of the 2nd number (-12) tells you to make the factors negative

I would use (x-2)(x-10)

Answer 6

Alright.. I didn't know about that part.

Answer 7

once you have it factored up top, we can cancel the (x-10) from top and bottom

Answer 8

but wait..

Answer 9

What if I don't know the factors with numbers?

Answer 10

I think that means you have to practice....
Here is a video, when you have time
http://www.khanacademy.org/math/algebra/polynomials/v/factoring-quadratic-expressions

Answer 11

but I'm Simplifying Algebraic Ratios

Answer 12

That means they think you know algebra, including factoring quadratics

Answer 13

Would the answer be x-2?

Answer 14

yes. you can test the answer
pick a simple number like x=0. If your answer is correct (x-2) with x=0 is 0-2= -2
replace x=0 into the original problem:
and you get 20/-10= -2 It matches!

Answer 15

I see. And I lied about the factoring thing, I can factor numbers that are even or divisible by 5

Answer 16

If the video helps, notice that Khan has LOTS of videos on pretty much any topic you might have a question on.