## careless850 Group Title Simplify.. again! 2 years ago 2 years ago

1. karatechopper Group Title

what to simplify?

2. careless850 Group Title

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

3. phi Group Title

you have to factor the top.

4. careless850 Group Title

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

5. phi Group Title

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)

6. careless850 Group Title

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

7. phi Group Title

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

8. careless850 Group Title

but wait..

9. careless850 Group Title

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

10. phi Group Title

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

11. careless850 Group Title

but I'm Simplifying Algebraic Ratios

12. phi Group Title

That means they think you know algebra, including factoring quadratics

13. careless850 Group Title

14. phi Group Title

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!

15. careless850 Group Title

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

16. phi Group Title

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