rodzz 3 years ago how to do quadratic functions pls xplain?

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1. joshi

ok so there are 3 ways to solve a quadratic equation: 1. factor 2. quadratic equation 3. complete the square

2. joshi

a quad usually in the form ax^2 + bx + c = y c is any number and a and b are the coefficients of x

3. rodzz

6x2 + 9x=? how to do?? i want xplaination ? can u pls elp? :)

4. rodzz

?

5. zepdrix

How to solve for x you mean? :o Or likeeee, how to graph and all that jazz? :D

6. rodzz

ya for x!

7. joshi

ok here's an example : x^2 + 5x + 6 = 0 one way to solve is to see what 2 numbers when multiplied equal 6, and when added equal 5. well 2x3=6, and 2+3 = 5 so this equation can also be written as x^2 + 2x + 3x + 6 = 0 now, we can factor it : x(x+2) + 3(x+2) = 0 and now we have (x+2) two times. in other words, both terms have an (x+2) in common so we can factor that out aswell: (x+2) (x+3) = 0 here, since multiplying these two together results in 0; that means either one of these can equal 0. because if you multiply a number by 0, you get 0, what i'm saying is: x+2 = 0, x+3=0 so then x=-2, x=-3 quadratic equations always have 2 answers.

8. zepdrix

Wow i didn't think you were going to say anything, you were writing for like 10 minutes lol.

9. joshi

hahaha yeah i backspaced a bunch of stuff and started over

10. rodzz

thnXXX :D

11. joshi

oh that actually made sense? lol ok

12. rodzz

wht do ya mean by tht? :O

13. joshi

oh nothing i just thought my explanation might have been confusing

14. rodzz

:P lol