## anonymous one year ago how do i do quadratics equations?? i get totally loss when im doing this

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1. anonymous

2. anonymous

Okay so first off lets identify quadratics

3. anonymous

4. anonymous

How do you know this you may ask? Well first off the X's exponent cuts in half

5. anonymous

Now to solve for a quadratic there are two ways that are most commonly used

6. anonymous

First there is the Quadratic Formula that you may or may not know, which is

7. anonymous

o.O im confused once more

8. anonymous

$b \pm \sqrt{b^2-4ac//2}$

9. anonymous

We could solve a quadratic if you have one available and i'll walk you through the steps.

10. anonymous

Would you like to solve a simple quadratic with me?

11. anonymous

ok?

12. anonymous

$8x^2+16x-20=0$

13. anonymous

Do you know how to solve this?

14. Nnesha

there is a typo you forgot - and a at the denominator $\huge\rm \frac{ \color{red}{- }b \pm \sqrt{b^2 -4ac} }{ 2\color{reD}{a} }$ quadratic formula where abc values are $\huge\rm Ax^2 +Bx+C=0$

15. anonymous

@Nnesha Sorry thank you for catching that :D

16. Nnesha

np :-)

17. anonymous

Ok onlii_bri lets try to solve to quadratic above, would you like to use the quadratic formula or split it up?

18. anonymous

|dw:1433635733307:dw|

19. anonymous

Whats that o-o

20. anonymous

dats how my teacher taught how to do it

21. anonymous

Lets do a different way for now,

22. anonymous

I'll work out the entire problem then i want you to try okay?

23. anonymous

ummm i have ncse in my country and my maths test is monday i need to learn it that way

24. anonymous

ok

25. anonymous

Idk how to do it that way sorry :( i only know how i learnt it from my algebra 2 and algebra 1 teachers.

26. anonymous

Maybe you are getting lost because your using a very traditional way of doing it

27. anonymous

im still on basic algebra

28. anonymous

Oh okay, thats alright let me give you a little lesson on quadratics and it will make it a whole lot easier to understand, ask me any questions as i go.

29. anonymous

$Ax^2+Bx+C=0$

30. anonymous

That is how you identify a quadratic

31. anonymous

Now they can also look like this 3x^2+9x+10=0

32. anonymous

Quadratics must always be equal to zero in order to be a quadratic.

33. anonymous

$3x^2+9x+10=0$

34. anonymous

Lets solve for the quadratic above very quickly.

35. anonymous

|dw:1433636159214:dw|

36. anonymous

First step is to multiply what is Squared by the constant. in this case we have 3

37. anonymous

3*10 = 30

38. anonymous

Now you must break down the multiples of 30 to see if any of them add up to 9.

39. anonymous

Well scratch that there are no multiplies of 30 that can add up or subtract to equal 9, so in this case we will use the quadratic formula.

40. anonymous

|dw:1433636365799:dw|

41. anonymous

|dw:1433636435572:dw|

42. anonymous

So far so good?

43. anonymous

Now you just plug in those numbers into the equation then plug into your calculator.

44. anonymous

If you need anymore help just ask, were all here to help.

45. anonymous

Also just so you know the -B is the lower case b in the equation above i just capitalized it by accident.

46. anonymous

47. anonymous

ok

48. anonymous

thanx

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