## anonymous one year ago Solve 3x2 + 4x = 2.

1. anonymous

I will fan and medal

2. anonymous

Is the 3x squared? is it 3x^2+4x=2

3. anonymous

yes

4. anonymous

Does it tell you how it wants it solved? Like a specific way?

5. anonymous

6. anonymous

do you know the formula by heart?

7. anonymous

x=-b+/- sqrt b^2 -4(a)(c) all over 2(a)

8. anonymous

yes

9. anonymous

Ok so first you need to set your equation equal to zero

10. anonymous

3x2+4x-2=0

11. anonymous

good. Now do you know your values for a, b, and c?

12. anonymous

Plug them into the equation?

13. anonymous

Yes

14. anonymous

(-3 $\pm \sqrt{16 +24}) / 6$

15. anonymous

the two lines are in continuation

16. anonymous

It should look like x=-4$\pm \sqrt{4^2-4(3)(-2)}$ over 2(3)

17. anonymous

So would it be -2 plus radical 10 all over 3|dw:1434907050388:dw|

18. anonymous

How did you get that?

19. anonymous

$-4+\sqrt{}$40

20. anonymous

$x=-4\pm \sqrt{16+24} \over 6$

21. anonymous

-4 plus or negative radical 40 all over 6

22. anonymous

yes

23. anonymous

Yes. then I simplifed

24. anonymous

a=3; not 4

25. anonymous

was I right?

26. anonymous

I used a=3

27. anonymous

What did you simplify to?

28. anonymous

29. anonymous

|dw:1434907346795:dw|

30. anonymous

How did you get there?

31. anonymous

no uhmwhat... u wrote -4 in two consecutive comments

32. anonymous

Where?

33. anonymous

guys? Was I right??

34. anonymous

let me check

35. anonymous

your answer should be $x=-4\pm2\sqrt{10} \over 6$

36. anonymous

37. anonymous

sorry... u r correct

38. anonymous

When you take the sqrt of 40 you find two radicals that multiply to give you 40 (sqrt 4 and sqrt 10) the sqrt of 4 is 2 but the 2 is attached to the sqrt of 10 so you cannot do -4=/- 2

39. anonymous

40. anonymous

I pointed out something I thought was wrong

41. anonymous

|dw:1434907656687:dw|

42. anonymous

|dw:1434907713281:dw|

43. anonymous

|dw:1434907746508:dw|

44. anonymous

I think what the answers did was simplify further. It makes sense in theory of what they did. Personally I don't simplify further because it doesn't give you as accurate a graph but if that is what the test or questions want then yes you are correct

45. anonymous

|dw:1434907790626:dw|